diff --git a/code/__DEFINES/quirks.dm b/code/__DEFINES/quirks.dm
new file mode 100644
index 00000000000..290fed93c95
--- /dev/null
+++ b/code/__DEFINES/quirks.dm
@@ -0,0 +1,14 @@
+//Medical Categories for quirks
+#define CAT_QUIRK_ALL 0
+#define CAT_QUIRK_NOTES 1
+#define CAT_QUIRK_MINOR_DISABILITY 2
+#define CAT_QUIRK_MAJOR_DISABILITY 3
+
+/// This quirk can only be applied to humans
+#define QUIRK_HUMAN_ONLY (1<<0)
+/// This quirk processes on SSquirks (and should implement quirk process)
+#define QUIRK_PROCESSES (1<<1)
+/// This quirk is has a visual aspect in that it changes how the player looks. Used in generating dummies.
+#define QUIRK_CHANGES_APPEARANCE (1<<2)
+/// The only thing this quirk effects is mood so it should be disabled if mood is
+#define QUIRK_MOODLET_BASED (1<<3)
diff --git a/code/__DEFINES/traits.dm b/code/__DEFINES/traits.dm
index 1fa4f4909ff..7e1c8a7d862 100644
--- a/code/__DEFINES/traits.dm
+++ b/code/__DEFINES/traits.dm
@@ -692,12 +692,6 @@ Remember to update _globalvars/traits.dm if you're adding/removing/renaming trai
 /// Echolocation has a higher range.
 #define TRAIT_ECHOLOCATION_EXTRA_RANGE "echolocation_extra_range"
 
-//Medical Categories for quirks
-#define CAT_QUIRK_ALL 0
-#define CAT_QUIRK_NOTES 1
-#define CAT_QUIRK_MINOR_DISABILITY 2
-#define CAT_QUIRK_MAJOR_DISABILITY 3
-
 // common trait sources
 #define TRAIT_GENERIC "generic"
 #define UNCONSCIOUS_TRAIT "unconscious"
diff --git a/code/controllers/subsystem/processing/quirks.dm b/code/controllers/subsystem/processing/quirks.dm
index cd75412aec5..d5bb0effa59 100644
--- a/code/controllers/subsystem/processing/quirks.dm
+++ b/code/controllers/subsystem/processing/quirks.dm
@@ -76,19 +76,19 @@ PROCESSING_SUBSYSTEM_DEF(quirks)
 			continue
 		hardcore_quirks[quirk_type] += hardcore_value
 
-/datum/controller/subsystem/processing/quirks/proc/AssignQuirks(mob/living/user, client/cli)
+/datum/controller/subsystem/processing/quirks/proc/AssignQuirks(mob/living/user, client/applied_client)
 	var/badquirk = FALSE
-	for(var/quirk_name in cli.prefs.all_quirks)
-		var/datum/quirk/Q = quirks[quirk_name]
-		if(Q)
-			if(user.add_quirk(Q))
+	for(var/quirk_name in applied_client.prefs.all_quirks)
+		var/datum/quirk/quirk_type = quirks[quirk_name]
+		if(ispath(quirk_type))
+			if(user.add_quirk(quirk_type, override_client = applied_client))
 				SSblackbox.record_feedback("nested tally", "quirks_taken", 1, list("[quirk_name]"))
 		else
-			stack_trace("Invalid quirk \"[quirk_name]\" in client [cli.ckey] preferences")
-			cli.prefs.all_quirks -= quirk_name
+			stack_trace("Invalid quirk \"[quirk_name]\" in client [applied_client.ckey] preferences")
+			applied_client.prefs.all_quirks -= quirk_name
 			badquirk = TRUE
 	if(badquirk)
-		cli.prefs.save_character()
+		applied_client.prefs.save_character()
 
 /*
  *Randomises the quirks for a specified mob
@@ -169,7 +169,7 @@ PROCESSING_SUBSYSTEM_DEF(quirks)
 		if (isnull(quirk))
 			continue
 
-		if (initial(quirk.mood_quirk) && CONFIG_GET(flag/disable_human_mood))
+		if ((initial(quirk.quirk_flags) & QUIRK_MOODLET_BASED) && CONFIG_GET(flag/disable_human_mood))
 			continue
 
 		var/blacklisted = FALSE
diff --git a/code/datums/quirks/_quirk.dm b/code/datums/quirks/_quirk.dm
index 1f24e1e3034..85885e62127 100644
--- a/code/datums/quirks/_quirk.dm
+++ b/code/datums/quirks/_quirk.dm
@@ -1,20 +1,29 @@
 //every quirk in this folder should be coded around being applied on spawn
 //these are NOT "mob quirks" like GOTTAGOFAST, but exist as a medium to apply them and other different effects
 /datum/quirk
+	/// The name of the quirk
 	var/name = "Test Quirk"
+	/// The description of the quirk
 	var/desc = "This is a test quirk."
+	/// What the quirk is worth in preferences, zero = neutral / free
 	var/value = 0
-	var/human_only = TRUE
-	var/gain_text
-	var/lose_text
-	var/medical_record_text //This text will appear on medical records for the trait. Not yet implemented
-	var/mood_quirk = FALSE //if true, this quirk affects mood and is unavailable if moodlets are disabled
-	var/mob_trait //if applicable, apply and remove this mob trait
-	/// Amount of points this trait is worth towards the hardcore character mode; minus points implies a positive quirk, positive means its hard. This is used to pick the quirks assigned to a hardcore character. 0 means its not available to hardcore draws.
-	var/hardcore_value = 0
+	/// Flags related to this quirk.
+	var/quirk_flags = QUIRK_HUMAN_ONLY
+	/// Reference to the mob currently tied to this quirk datum. Quirks are not singletons.
 	var/mob/living/quirk_holder
-	/// This quirk should START_PROCESSING when added and STOP_PROCESSING when removed.
-	var/processing_quirk = FALSE
+	/// Text displayed when this quirk is assigned to a mob (and not transferred)
+	var/gain_text
+	/// Text displayed when this quirk is removed from a mob (and not transferred)
+	var/lose_text
+	///This text will appear on medical records for the trait.
+	var/medical_record_text
+	/// if applicable, apply and remove this mob trait
+	var/mob_trait
+	/// Amount of points this trait is worth towards the hardcore character mode.
+	/// Minus points implies a positive quirk, positive means its hard.
+	/// This is used to pick the quirks assigned to a hardcore character.
+	//// 0 means its not available to hardcore draws.
+	var/hardcore_value = 0
 	/// When making an abstract quirk (in OOP terms), don't forget to set this var to the type path for that abstract quirk.
 	var/abstract_parent_type = /datum/quirk
 	/// The icon to show in the preferences menu.
@@ -45,11 +54,11 @@
  * * new_holder - The mob to add this quirk to.
  * * quirk_transfer - If this is being added to the holder as part of a quirk transfer. Quirks can use this to decide not to spawn new items or apply any other one-time effects.
  */
-/datum/quirk/proc/add_to_holder(mob/living/new_holder, quirk_transfer = FALSE)
+/datum/quirk/proc/add_to_holder(mob/living/new_holder, quirk_transfer = FALSE, client/client_source)
 	if(!new_holder)
 		CRASH("Quirk attempted to be added to null mob.")
 
-	if(human_only && !ishuman(new_holder))
+	if((quirk_flags & QUIRK_HUMAN_ONLY) && !ishuman(new_holder))
 		CRASH("Human only quirk attempted to be added to non-human mob.")
 
 	if(new_holder.has_quirk(type))
@@ -60,19 +69,21 @@
 
 	quirk_holder = new_holder
 	quirk_holder.quirks += src
+	// If we weren't passed a client source try to use a present one
+	client_source ||= quirk_holder.client
 
 	if(mob_trait)
 		ADD_TRAIT(quirk_holder, mob_trait, QUIRK_TRAIT)
 
-	add()
+	add(client_source)
 
-	if(processing_quirk)
+	if(quirk_flags & QUIRK_PROCESSES)
 		START_PROCESSING(SSquirks, src)
 
 	if(!quirk_transfer)
 		if(gain_text)
 			to_chat(quirk_holder, gain_text)
-		add_unique()
+		add_unique(client_source)
 
 		if(quirk_holder.client)
 			post_add()
@@ -98,7 +109,7 @@
 	if(mob_trait)
 		REMOVE_TRAIT(quirk_holder, mob_trait, QUIRK_TRAIT)
 
-	if(processing_quirk)
+	if(quirk_flags & QUIRK_PROCESSES)
 		STOP_PROCESSING(SSquirks, src)
 
 	remove()
@@ -119,13 +130,23 @@
 		post_add()
 
 /// Any effect that should be applied every single time the quirk is added to any mob, even when transferred.
-/datum/quirk/proc/add()
-/// Any effects from the proc that should not be done multiple times if the quirk is transferred between mobs. Put stuff like spawning items in here.
-/datum/quirk/proc/add_unique()
+/datum/quirk/proc/add(client/client_source)
+	return
+
+/// Any effects from the proc that should not be done multiple times if the quirk is transferred between mobs.
+/// Put stuff like spawning items in here.
+/datum/quirk/proc/add_unique(client/client_source)
+	return
+
 /// Removal of any reversible effects added by the quirk.
 /datum/quirk/proc/remove()
-/// Any special effects or chat messages which should be applied. This proc is guaranteed to run if the mob has a client when the quirk is added. Otherwise, it runs once on the next COMSIG_MOB_LOGIN.
+	return
+
+/// Any special effects or chat messages which should be applied.
+/// This proc is guaranteed to run if the mob has a client when the quirk is added.
+/// Otherwise, it runs once on the next COMSIG_MOB_LOGIN.
 /datum/quirk/proc/post_add()
+	return
 
 /// Subtype quirk that has some bonus logic to spawn items for the player.
 /datum/quirk/item_quirk
@@ -219,12 +240,13 @@
 		return medical ? "No issues have been declared." : "None"
 	return medical ?  dat.Join("<br>") : dat.Join(", ")
 
-/mob/living/proc/cleanse_trait_datums() //removes all trait datums
-	for(var/V in quirks)
-		var/datum/quirk/T = V
-		qdel(T)
+/mob/living/proc/cleanse_quirk_datums() //removes all trait datums
+	QDEL_LIST(quirks)
+
+/mob/living/proc/transfer_quirk_datums(mob/living/to_mob)
+	// We could be done before the client was moved or after the client was moved
+	var/datum/preferences/to_pass = client || to_mob.client
 
-/mob/living/proc/transfer_trait_datums(mob/living/to_mob)
 	for(var/datum/quirk/quirk as anything in quirks)
 		quirk.remove_from_current_holder(quirk_transfer = TRUE)
-		quirk.add_to_holder(to_mob, quirk_transfer = TRUE)
+		quirk.add_to_holder(to_mob, quirk_transfer = TRUE, client_source = to_pass)
diff --git a/code/datums/quirks/negative_quirks.dm b/code/datums/quirks/negative_quirks.dm
index f51bb7bfff2..2ea1b41004d 100644
--- a/code/datums/quirks/negative_quirks.dm
+++ b/code/datums/quirks/negative_quirks.dm
@@ -5,7 +5,7 @@
 	desc = "Thanks to your poor posture, backpacks and other bags never sit right on your back. More evenly weighted objects are fine, though."
 	icon = "hiking"
 	value = -8
-	mood_quirk = TRUE
+	quirk_flags = QUIRK_HUMAN_ONLY|QUIRK_MOODLET_BASED
 	gain_text = "<span class='danger'>Your back REALLY hurts!</span>"
 	lose_text = "<span class='notice'>Your back feels better.</span>"
 	medical_record_text = "Patient scans indicate severe and chronic back pain."
@@ -13,7 +13,7 @@
 	mail_goodies = list(/obj/item/cane)
 	var/datum/weakref/backpack
 
-/datum/quirk/badback/add()
+/datum/quirk/badback/add(client/client_source)
 	var/mob/living/carbon/human/human_holder = quirk_holder
 	var/obj/item/storage/backpack/equipped_backpack = human_holder.back
 	if(istype(equipped_backpack))
@@ -60,7 +60,7 @@
 	lose_text = "<span class='notice'>You feel vigorous again.</span>"
 	medical_record_text = "Patient requires regular treatment for blood loss due to low production of blood."
 	hardcore_value = 8
-	processing_quirk = TRUE
+	quirk_flags = QUIRK_HUMAN_ONLY|QUIRK_PROCESSES
 	mail_goodies = list(/obj/item/reagent_containers/blood/o_minus) // universal blood type that is safe for all
 	var/min_blood = BLOOD_VOLUME_SAFE - 25 // just barely survivable without treatment
 	var/drain_rate = 0.275
@@ -87,12 +87,13 @@
 	lose_text = "<span class='notice'>You miraculously gain back your vision.</span>"
 	medical_record_text = "Patient has permanent blindness."
 	hardcore_value = 15
+	quirk_flags = QUIRK_HUMAN_ONLY|QUIRK_CHANGES_APPEARANCE
 	mail_goodies = list(/obj/item/clothing/glasses/sunglasses, /obj/item/cane/white)
 
-/datum/quirk/item_quirk/blindness/add_unique()
+/datum/quirk/item_quirk/blindness/add_unique(client/client_source)
 	give_item_to_holder(/obj/item/clothing/glasses/blindfold/white, list(LOCATION_EYES = ITEM_SLOT_EYES, LOCATION_BACKPACK = ITEM_SLOT_BACKPACK, LOCATION_HANDS = ITEM_SLOT_HANDS))
 
-/datum/quirk/item_quirk/blindness/add()
+/datum/quirk/item_quirk/blindness/add(client/client_source)
 	quirk_holder.become_blind(QUIRK_TRAIT)
 
 /datum/quirk/item_quirk/blindness/remove()
@@ -112,10 +113,10 @@
 	lose_text = "<span class='notice'>You feel wrinkled again.</span>"
 	medical_record_text = "Patient has a tumor in their brain that is slowly driving them to brain death."
 	hardcore_value = 12
-	processing_quirk = TRUE
+	quirk_flags = QUIRK_HUMAN_ONLY|QUIRK_PROCESSES
 	mail_goodies = list(/obj/item/storage/pill_bottle/mannitol/braintumor)
 
-/datum/quirk/item_quirk/brainproblems/add_unique()
+/datum/quirk/item_quirk/brainproblems/add_unique(client/client_source)
 	give_item_to_holder(
 		/obj/item/storage/pill_bottle/mannitol/braintumor,
 		list(
@@ -148,7 +149,7 @@
 	hardcore_value = 12
 	mail_goodies = list(/obj/item/clothing/mask/whistle)
 
-/datum/quirk/item_quirk/deafness/add_unique()
+/datum/quirk/item_quirk/deafness/add_unique(client/client_source)
 	give_item_to_holder(/obj/item/clothing/accessory/deaf_pin, list(LOCATION_BACKPACK = ITEM_SLOT_BACKPACK, LOCATION_HANDS = ITEM_SLOT_HANDS))
 
 /datum/quirk/depression
@@ -160,7 +161,7 @@
 	gain_text = "<span class='danger'>You start feeling depressed.</span>"
 	lose_text = "<span class='notice'>You no longer feel depressed.</span>" //if only it were that easy!
 	medical_record_text = "Patient has a mild mood disorder causing them to experience acute episodes of depression."
-	mood_quirk = TRUE
+	quirk_flags = QUIRK_HUMAN_ONLY|QUIRK_MOODLET_BASED
 	hardcore_value = 2
 	mail_goodies = list(/obj/item/storage/pill_bottle/happinesspsych)
 
@@ -169,15 +170,14 @@
 	desc = "You are the current owner of an heirloom, passed down for generations. You have to keep it safe!"
 	icon = "toolbox"
 	value = -2
-	mood_quirk = TRUE
 	medical_record_text = "Patient demonstrates an unnatural attachment to a family heirloom."
 	hardcore_value = 1
-	processing_quirk = TRUE
+	quirk_flags = QUIRK_HUMAN_ONLY|QUIRK_PROCESSES|QUIRK_MOODLET_BASED
 	/// A weak reference to our heirloom.
 	var/datum/weakref/heirloom
 	mail_goodies = list(/obj/item/storage/secure/briefcase)
 
-/datum/quirk/item_quirk/family_heirloom/add_unique()
+/datum/quirk/item_quirk/family_heirloom/add_unique(client/client_source)
 	var/mob/living/carbon/human/human_holder = quirk_holder
 	var/obj/item/heirloom_type
 
@@ -266,7 +266,7 @@
 			/obj/item/clothing/mask/luchador/tecnicos,
 		)
 
-/datum/quirk/glass_jaw/add()
+/datum/quirk/glass_jaw/add(client/client_source)
 	RegisterSignal(quirk_holder, COMSIG_MOB_APPLY_DAMAGE, PROC_REF(punch_out))
 
 /datum/quirk/glass_jaw/remove()
@@ -332,7 +332,7 @@
 	hardcore_value = 3
 	mail_goodies = list(/obj/effect/spawner/random/entertainment/plushie_delux)
 
-/datum/quirk/hypersensitive/add()
+/datum/quirk/hypersensitive/add(client/client_source)
 	if (quirk_holder.mob_mood)
 		quirk_holder.mob_mood.mood_modifier += 0.5
 
@@ -361,26 +361,29 @@
 	lose_text = "<span class='notice'>You start seeing faraway things normally again.</span>"
 	medical_record_text = "Patient requires prescription glasses in order to counteract nearsightedness."
 	hardcore_value = 5
+	quirk_flags = QUIRK_HUMAN_ONLY|QUIRK_CHANGES_APPEARANCE
 	mail_goodies = list(/obj/item/clothing/glasses/regular) // extra pair if orginal one gets broken by somebody mean
-	var/glasses
 
-/datum/quirk/item_quirk/nearsighted/add_unique()
-	glasses = glasses || quirk_holder.client?.prefs?.read_preference(/datum/preference/choiced/glasses)
-	switch(glasses)
+/datum/quirk/item_quirk/nearsighted/add_unique(client/client_source)
+	var/glasses_name = client_source?.prefs.read_preference(/datum/preference/choiced/glasses) || "Regular"
+	var/obj/item/clothing/glasses/glasses_type
+	switch(glasses_name)
 		if ("Thin")
-			glasses = /obj/item/clothing/glasses/regular/thin
+			glasses_type = /obj/item/clothing/glasses/regular/thin
 		if ("Circle")
-			glasses = /obj/item/clothing/glasses/regular/circle
+			glasses_type = /obj/item/clothing/glasses/regular/circle
 		if ("Hipster")
-			glasses = /obj/item/clothing/glasses/regular/hipster
-		if ("Modern")
-			glasses = /obj/item/clothing/glasses/betterunshit
+			glasses_type = /obj/item/clothing/glasses/regular/hipster
 		else
-			glasses = /obj/item/clothing/glasses/regular
+			glasses_type = /obj/item/clothing/glasses/regular
 
-	give_item_to_holder(glasses, list(LOCATION_EYES = ITEM_SLOT_EYES, LOCATION_BACKPACK = ITEM_SLOT_BACKPACK, LOCATION_HANDS = ITEM_SLOT_HANDS))
+	give_item_to_holder(glasses_type, list(
+		LOCATION_EYES = ITEM_SLOT_EYES,
+		LOCATION_BACKPACK = ITEM_SLOT_BACKPACK,
+		LOCATION_HANDS = ITEM_SLOT_HANDS,
+	))
 
-/datum/quirk/item_quirk/nearsighted/add()
+/datum/quirk/item_quirk/nearsighted/add(client/client_source)
 	quirk_holder.become_nearsighted(QUIRK_TRAIT)
 
 /datum/quirk/item_quirk/nearsighted/remove()
@@ -395,7 +398,7 @@
 	hardcore_value = 5
 	mail_goodies = list(/obj/effect/spawner/random/engineering/flashlight)
 
-/datum/quirk/nyctophobia/add()
+/datum/quirk/nyctophobia/add(client/client_source)
 	RegisterSignal(quirk_holder, COMSIG_MOVABLE_MOVED, PROC_REF(on_holder_moved))
 
 /datum/quirk/nyctophobia/remove()
@@ -450,14 +453,13 @@
 	desc = "Your legs do not function. Nothing will ever fix this. But hey, free wheelchair!"
 	icon = "wheelchair"
 	value = -12
-	human_only = TRUE
 	gain_text = null // Handled by trauma.
 	lose_text = null
 	medical_record_text = "Patient has an untreatable impairment in motor function in the lower extremities."
 	hardcore_value = 15
 	mail_goodies = list(/obj/vehicle/ridden/wheelchair/motorized) //yes a fullsized unfolded motorized wheelchair does fit
 
-/datum/quirk/paraplegic/add_unique()
+/datum/quirk/paraplegic/add_unique(client/client_source)
 	if(quirk_holder.buckled) // Handle late joins being buckled to arrival shuttle chairs.
 		quirk_holder.buckled.unbuckle_mob(quirk_holder)
 
@@ -465,7 +467,7 @@
 	var/obj/structure/chair/spawn_chair = locate() in holder_turf
 
 	var/obj/vehicle/ridden/wheelchair/wheels
-	if(quirk_holder.client?.get_award_status(/datum/award/score/hardcore_random) >= 5000) //More than 5k score? you unlock the gamer wheelchair.
+	if(client_source?.get_award_status(/datum/award/score/hardcore_random) >= 5000) //More than 5k score? you unlock the gamer wheelchair.
 		wheels = new /obj/vehicle/ridden/wheelchair/gold(holder_turf)
 	else
 		wheels = new(holder_turf)
@@ -480,7 +482,7 @@
 		if(dropped_item.fingerprintslast == quirk_holder.ckey)
 			quirk_holder.put_in_hands(dropped_item)
 
-/datum/quirk/paraplegic/add()
+/datum/quirk/paraplegic/add(client/client_source)
 	var/mob/living/carbon/human/human_holder = quirk_holder
 	human_holder.gain_trauma(/datum/brain_trauma/severe/paralysis/paraplegic, TRAUMA_RESILIENCE_ABSOLUTE)
 
@@ -516,9 +518,10 @@
 	var/slot_string = "limb"
 	medical_record_text = "During physical examination, patient was found to have a prosthetic limb."
 	hardcore_value = 3
+	quirk_flags = QUIRK_HUMAN_ONLY|QUIRK_CHANGES_APPEARANCE
 	mail_goodies = list(/obj/item/weldingtool/mini, /obj/item/stack/cable_coil/five)
 
-/datum/quirk/prosthetic_limb/add_unique()
+/datum/quirk/prosthetic_limb/add_unique(client/client_source)
 	var/limb_slot = pick(BODY_ZONE_L_ARM, BODY_ZONE_R_ARM, BODY_ZONE_L_LEG, BODY_ZONE_R_LEG)
 	var/mob/living/carbon/human/human_holder = quirk_holder
 	var/obj/item/bodypart/prosthetic
@@ -548,8 +551,9 @@
 	value = -6
 	medical_record_text = "During physical examination, patient was found to have all prosthetic limbs."
 	hardcore_value = 6
+	quirk_flags = QUIRK_HUMAN_ONLY|QUIRK_CHANGES_APPEARANCE
 
-/datum/quirk/quadruple_amputee/add_unique()
+/datum/quirk/quadruple_amputee/add_unique(client/client_source)
 	var/mob/living/carbon/human/human_holder = quirk_holder
 	human_holder.del_and_replace_bodypart(new /obj/item/bodypart/arm/left/robot/surplus)
 	human_holder.del_and_replace_bodypart(new /obj/item/bodypart/arm/right/robot/surplus)
@@ -587,7 +591,7 @@
 	/// Weakref to the trauma we give out
 	var/datum/weakref/added_trama_ref
 
-/datum/quirk/insanity/add()
+/datum/quirk/insanity/add(client/client_source)
 	if(!iscarbon(quirk_holder))
 		return
 	var/mob/living/carbon/carbon_quirk_holder = quirk_holder
@@ -630,7 +634,7 @@
 	mail_goodies = list(/obj/item/storage/pill_bottle/psicodine)
 	var/dumb_thing = TRUE
 
-/datum/quirk/social_anxiety/add()
+/datum/quirk/social_anxiety/add(client/client_source)
 	RegisterSignal(quirk_holder, COMSIG_MOB_EYECONTACT, PROC_REF(eye_contact))
 	RegisterSignal(quirk_holder, COMSIG_MOB_EXAMINATE, PROC_REF(looks_at_floor))
 	RegisterSignal(quirk_holder, COMSIG_MOB_SAY, PROC_REF(handle_speech))
@@ -740,7 +744,7 @@
 	gain_text = "<span class='danger'>You suddenly feel the craving for drugs.</span>"
 	medical_record_text = "Patient has a history of hard drugs."
 	hardcore_value = 4
-	processing_quirk = TRUE
+	quirk_flags = QUIRK_HUMAN_ONLY|QUIRK_PROCESSES
 	mail_goodies = list(/obj/effect/spawner/random/contraband/narcotics)
 	var/drug_list = list(/datum/reagent/drug/blastoff, /datum/reagent/drug/krokodil, /datum/reagent/medicine/morphine, /datum/reagent/drug/happiness, /datum/reagent/drug/methamphetamine) //List of possible IDs
 	var/datum/reagent/reagent_type //!If this is defined, reagent_id will be unused and the defined reagent type will be instead.
@@ -753,7 +757,7 @@
 	var/next_process = 0 //! ticker for processing
 	var/drug_flavour_text = "Better hope you don't run out..."
 
-/datum/quirk/item_quirk/junkie/add_unique()
+/datum/quirk/item_quirk/junkie/add_unique(client/client_source)
 	var/mob/living/carbon/human/human_holder = quirk_holder
 
 	if(!reagent_type)
@@ -893,13 +897,13 @@
 	lose_text = "<span class='notice'>You feel your immune system phase back into perfect shape.</span>"
 	medical_record_text = "Patient's immune system responds violently to certain chemicals."
 	hardcore_value = 3
-	processing_quirk = TRUE
+	quirk_flags = QUIRK_HUMAN_ONLY|QUIRK_PROCESSES
 	mail_goodies = list(/obj/item/reagent_containers/hypospray/medipen) // epinephrine medipen stops allergic reactions
 	var/list/allergies = list()
 	var/list/blacklist = list(/datum/reagent/medicine/c2,/datum/reagent/medicine/epinephrine,/datum/reagent/medicine/adminordrazine,/datum/reagent/medicine/omnizine/godblood,/datum/reagent/medicine/cordiolis_hepatico,/datum/reagent/medicine/synaphydramine,/datum/reagent/medicine/diphenhydramine)
 	var/allergy_string
 
-/datum/quirk/item_quirk/allergic/add_unique()
+/datum/quirk/item_quirk/allergic/add_unique(client/client_source)
 	var/list/chem_list = subtypesof(/datum/reagent/medicine) - blacklist
 	var/list/allergy_chem_names = list()
 	for(var/i in 0 to 5)
@@ -956,11 +960,11 @@
 	gain_text = "<span class='danger'>You just want people to leave you alone.</span>"
 	lose_text = "<span class='notice'>You could use a big hug.</span>"
 	medical_record_text = "Patient has disdain for being touched. Potentially has undiagnosed haphephobia."
-	mood_quirk = TRUE
+	quirk_flags = QUIRK_HUMAN_ONLY|QUIRK_MOODLET_BASED
 	hardcore_value = 1
 	mail_goodies = list(/obj/item/reagent_containers/spray/pepper) // show me on the doll where the bad man touched you
 
-/datum/quirk/bad_touch/add()
+/datum/quirk/bad_touch/add(client/client_source)
 	RegisterSignals(quirk_holder, list(COMSIG_LIVING_GET_PULLED, COMSIG_CARBON_HELP_ACT), PROC_REF(uncomfortable_touch))
 
 /datum/quirk/bad_touch/remove()
@@ -986,7 +990,7 @@
 	value = -4
 	medical_record_text = "Patient demonstrates a fear of tight spaces."
 	hardcore_value = 5
-	processing_quirk = TRUE
+	quirk_flags = QUIRK_HUMAN_ONLY|QUIRK_PROCESSES
 	mail_goodies = list(/obj/item/reagent_containers/syringe/convermol) // to help breathing
 
 /datum/quirk/claustrophobia/remove()
@@ -1044,12 +1048,24 @@
 	hardcore_value = 8
 	mail_goodies = list(/obj/item/pai_card) // can read things for you
 
+
+/datum/quirk/mute
+	name = "Mute"
+	desc = "For some reason you are completely unable to speak."
+	icon = "volume-xmark"
+	value = -4
+	mob_trait = TRAIT_MUTE
+	gain_text = span_danger("You find yourself unable to speak!")
+	lose_text = span_notice("You feel a growing strength in your vocal chords.")
+	medical_record_text = "The patient is unable to use their voice in any capacity."
+	hardcore_value = 4
+
 /datum/quirk/body_purist
 	name = "Body Purist"
 	desc = "You believe your body is a temple and its natural form is an embodiment of perfection. Accordingly, you despise the idea of ever augmenting it with unnatural parts, cybernetic, prosthetic, or anything like it."
 	icon = "person-rays"
 	value = -2
-	mood_quirk = TRUE
+	quirk_flags = QUIRK_HUMAN_ONLY|QUIRK_MOODLET_BASED
 	gain_text = "<span class='danger'>You now begin to hate the idea of having cybernetic implants.</span>"
 	lose_text = "<span class='notice'>Maybe cybernetics aren't so bad. You now feel okay with augmentations and prosthetics.</span>"
 	medical_record_text = "This patient has disclosed an extreme hatred for unnatural bodyparts and augmentations."
@@ -1057,7 +1073,7 @@
 	mail_goodies = list(/obj/item/paper/pamphlet/cybernetics)
 	var/cybernetics_level = 0
 
-/datum/quirk/body_purist/add()
+/datum/quirk/body_purist/add(client/client_source)
 	check_cybernetics()
 	RegisterSignal(quirk_holder, COMSIG_CARBON_GAIN_ORGAN, PROC_REF(on_organ_gain))
 	RegisterSignal(quirk_holder, COMSIG_CARBON_LOSE_ORGAN, PROC_REF(on_organ_lose))
@@ -1116,14 +1132,3 @@
 	if(!IS_ORGANIC_LIMB(old_limb))
 		cybernetics_level--
 		update_mood()
-
-/datum/quirk/mute
-	name = "Mute"
-	desc = "For some reason you are completely unable to speak."
-	icon = "volume-xmark"
-	value = -4
-	mob_trait = TRAIT_MUTE
-	gain_text = span_danger("You find yourself unable to speak!")
-	lose_text = span_notice("You feel a growing strength in your vocal chords.")
-	medical_record_text = "The patient is unable to use their voice in any capacity."
-	hardcore_value = 4
diff --git a/code/datums/quirks/neutral_quirks.dm b/code/datums/quirks/neutral_quirks.dm
index f8e944577e3..da9b0d307b6 100644
--- a/code/datums/quirks/neutral_quirks.dm
+++ b/code/datums/quirks/neutral_quirks.dm
@@ -44,7 +44,7 @@
 	medical_record_text = "Patient does not speak Galactic Common and may require an interpreter."
 	mail_goodies = list(/obj/item/taperecorder) // for translation
 
-/datum/quirk/foreigner/add()
+/datum/quirk/foreigner/add(client/client_source)
 	var/mob/living/carbon/human/human_holder = quirk_holder
 	human_holder.add_blocked_language(/datum/language/common)
 	if(ishumanbasic(human_holder))
@@ -66,7 +66,7 @@
 	medical_record_text = "Patient reports a vegetarian diet."
 	mail_goodies = list(/obj/effect/spawner/random/food_or_drink/salad)
 
-/datum/quirk/vegetarian/add()
+/datum/quirk/vegetarian/add(client/client_source)
 	var/mob/living/carbon/human/human_holder = quirk_holder
 	var/datum/species/species = human_holder.dna.species
 	species.liked_food &= ~MEAT
@@ -109,7 +109,7 @@
 	medical_record_text = "Patient demonstrates a pathological love of pineapple."
 	mail_goodies = list(/obj/item/food/pizzaslice/pineapple)
 
-/datum/quirk/pineapple_liker/add()
+/datum/quirk/pineapple_liker/add(client/client_source)
 	var/mob/living/carbon/human/human_holder = quirk_holder
 	var/datum/species/species = human_holder.dna.species
 	species.liked_food |= PINEAPPLE
@@ -141,7 +141,7 @@
 		/obj/item/food/pizzaslice/sassysage,
 	)
 
-/datum/quirk/pineapple_hater/add()
+/datum/quirk/pineapple_hater/add(client/client_source)
 	var/mob/living/carbon/human/human_holder = quirk_holder
 	var/datum/species/species = human_holder.dna.species
 	species.disliked_food |= PINEAPPLE
@@ -167,7 +167,7 @@
 	medical_record_text = "Patient demonstrates irregular nutrition preferences."
 	mail_goodies = list(/obj/item/food/urinalcake, /obj/item/food/badrecipe) // Mhhhmmm yummy
 
-/datum/quirk/deviant_tastes/add()
+/datum/quirk/deviant_tastes/add(client/client_source)
 	var/mob/living/carbon/human/human_holder = quirk_holder
 	var/datum/species/species = human_holder.dna.species
 	var/liked = species.liked_food
@@ -192,36 +192,27 @@
 	name = "Heterochromatic"
 	desc = "One of your eyes is a different color than the other!"
 	icon = "eye-low-vision" // Ignore the icon name, its actually a fairly good representation of different color eyes
+	quirk_flags = QUIRK_HUMAN_ONLY|QUIRK_CHANGES_APPEARANCE
 	value = 0
 	mail_goodies = list(/obj/item/clothing/glasses/eyepatch)
-	var/color
 
-/datum/quirk/heterochromatic/add()
-	color = color || quirk_holder.client?.prefs?.read_preference(/datum/preference/color/heterochromatic)
+// Only your first eyes are heterochromatic
+// If someone comes and says "well mr coder you can have DNA bound heterochromia so it's not unrealistic
+// to allow all inserted replacement eyes to become heterochromatic or for it to transfer between mobs"
+// Then just change this to [proc/add] I really don't care
+/datum/quirk/heterochromatic/add_unique(client/client_source)
+	var/color = client_source?.prefs.read_preference(/datum/preference/color/heterochromatic)
 	if(!color)
 		return
 
-	link_to_holder()
+	apply_heterochromatic_eyes(color)
 
-/datum/quirk/heterochromatic/post_add()
-	if(color)
-		return
-
-	color = quirk_holder.client?.prefs?.read_preference(/datum/preference/color/heterochromatic)
-	if(!color)
-		return
-
-	link_to_holder()
-
-/datum/quirk/heterochromatic/remove()
-	UnregisterSignal(quirk_holder, COMSIG_CARBON_LOSE_ORGAN)
-
-/datum/quirk/heterochromatic/proc/link_to_holder()
+/// Applies the passed color to this mob's eyes
+/datum/quirk/heterochromatic/proc/apply_heterochromatic_eyes(color)
 	var/mob/living/carbon/human/human_holder = quirk_holder
+	var/was_not_hetero = !human_holder.eye_color_heterochromatic
 	human_holder.eye_color_heterochromatic = TRUE
 	human_holder.eye_color_right = color
-	// We set override to TRUE as link to holder will be called whenever the preference is applied, given this quirk exists on the mob
-	RegisterSignal(human_holder, COMSIG_CARBON_LOSE_ORGAN, PROC_REF(check_eye_removal), override=TRUE)
 
 	var/obj/item/organ/internal/eyes/eyes_of_the_holder = quirk_holder.getorgan(/obj/item/organ/internal/eyes)
 	if(!eyes_of_the_holder)
@@ -231,6 +222,15 @@
 	eyes_of_the_holder.old_eye_color_right = color
 	eyes_of_the_holder.refresh()
 
+	if(was_not_hetero)
+		RegisterSignal(human_holder, COMSIG_CARBON_LOSE_ORGAN, PROC_REF(check_eye_removal))
+
+/datum/quirk/heterochromatic/remove()
+	var/mob/living/carbon/human/human_holder = quirk_holder
+	human_holder.eye_color_heterochromatic = FALSE
+	human_holder.eye_color_right = human_holder.eye_color_left
+	UnregisterSignal(human_holder, COMSIG_CARBON_LOSE_ORGAN)
+
 /datum/quirk/heterochromatic/proc/check_eye_removal(datum/source, obj/item/organ/internal/eyes/removed)
 	SIGNAL_HANDLER
 
@@ -240,7 +240,7 @@
 	// Eyes were removed, remove heterochromia from the human holder and bid them adieu
 	var/mob/living/carbon/human/human_holder = quirk_holder
 	human_holder.eye_color_heterochromatic = FALSE
-	human_holder.eye_color_right = initial(human_holder.eye_color_right)
+	human_holder.eye_color_right = human_holder.eye_color_left
 	UnregisterSignal(human_holder, COMSIG_CARBON_LOSE_ORGAN)
 
 /datum/quirk/monochromatic
@@ -256,7 +256,7 @@
 		/obj/item/clothing/head/fedora/white,
 	)
 
-/datum/quirk/monochromatic/add()
+/datum/quirk/monochromatic/add(client/client_source)
 	quirk_holder.add_client_colour(/datum/client_colour/monochrome)
 
 /datum/quirk/monochromatic/post_add()
@@ -273,21 +273,16 @@
 	icon = "spider"
 	value = 0
 	medical_record_text = "Patient has an irrational fear of something."
-	var/phobia
 	mail_goodies = list(/obj/item/clothing/glasses/blindfold, /obj/item/storage/pill_bottle/psicodine)
 
-/datum/quirk/phobia/add()
-	phobia = phobia || quirk_holder.client?.prefs?.read_preference(/datum/preference/choiced/phobia)
-
-	if(phobia)
-		var/mob/living/carbon/human/human_holder = quirk_holder
-		human_holder.gain_trauma(new /datum/brain_trauma/mild/phobia(phobia), TRAUMA_RESILIENCE_ABSOLUTE)
-
-/datum/quirk/phobia/post_add()
+// Phobia will follow you between transfers
+/datum/quirk/phobia/add(client/client_source)
+	var/phobia = client_source?.prefs.read_preference(/datum/preference/choiced/phobia)
 	if(!phobia)
-		var/mob/living/carbon/human/human_holder = quirk_holder
-		phobia = human_holder.client.prefs.read_preference(/datum/preference/choiced/phobia)
-		human_holder.gain_trauma(new /datum/brain_trauma/mild/phobia(phobia), TRAUMA_RESILIENCE_ABSOLUTE)
+		return
+
+	var/mob/living/carbon/human/human_holder = quirk_holder
+	human_holder.gain_trauma(new /datum/brain_trauma/mild/phobia(phobia), TRAUMA_RESILIENCE_ABSOLUTE)
 
 /datum/quirk/phobia/remove()
 	var/mob/living/carbon/human/human_holder = quirk_holder
@@ -315,7 +310,7 @@
 	/// The user's starting hairstyle
 	var/old_hair
 
-/datum/quirk/item_quirk/bald/add()
+/datum/quirk/item_quirk/bald/add(client/client_source)
 	var/mob/living/carbon/human/human_holder = quirk_holder
 	old_hair = human_holder.hairstyle
 	human_holder.hairstyle = "Bald"
@@ -323,7 +318,7 @@
 	RegisterSignal(human_holder, COMSIG_CARBON_EQUIP_HAT, PROC_REF(equip_hat))
 	RegisterSignal(human_holder, COMSIG_CARBON_UNEQUIP_HAT, PROC_REF(unequip_hat))
 
-/datum/quirk/item_quirk/bald/add_unique()
+/datum/quirk/item_quirk/bald/add_unique(client/client_source)
 	var/obj/item/clothing/head/wig/natural/baldie_wig = new(get_turf(quirk_holder))
 
 	if (old_hair == "Bald")
@@ -369,7 +364,7 @@
 	medical_record_text = "Patient mentions photography as a stress-relieving hobby."
 	mail_goodies = list(/obj/item/camera_film)
 
-/datum/quirk/item_quirk/photographer/add_unique()
+/datum/quirk/item_quirk/photographer/add_unique(client/client_source)
 	var/mob/living/carbon/human/human_holder = quirk_holder
 	var/obj/item/storage/photo_album/personal/photo_album = new(get_turf(human_holder))
 	photo_album.persistence_id = "personal_[human_holder.last_mind?.key]" // this is a persistent album, the ID is tied to the account's key to avoid tampering
@@ -397,7 +392,7 @@
 	medical_record_text = "Patient enjoys dyeing their hair with pretty colors."
 	mail_goodies = list(/obj/item/dyespray)
 
-/datum/quirk/item_quirk/colorist/add_unique()
+/datum/quirk/item_quirk/colorist/add_unique(client/client_source)
 	give_item_to_holder(/obj/item/dyespray, list(LOCATION_BACKPACK = ITEM_SLOT_BACKPACK, LOCATION_HANDS = ITEM_SLOT_HANDS))
 */
 
@@ -415,7 +410,7 @@
 	/// Timer for gaming withdrawal to kick in
 	var/gaming_withdrawal_timer = TIMER_ID_NULL
 
-/datum/quirk/gamer/add()
+/datum/quirk/gamer/add(client/client_source)
 	// Gamer diet
 	var/mob/living/carbon/human/human_holder = quirk_holder
 	var/datum/species/species = human_holder.dna.species
@@ -438,7 +433,7 @@
 	UnregisterSignal(human_holder, COMSIG_MOB_LOST_VIDEOGAME)
 	UnregisterSignal(human_holder, COMSIG_MOB_PLAYED_VIDEOGAME)
 
-/datum/quirk/gamer/add_unique()
+/datum/quirk/gamer/add_unique(client/client_source)
 	// The gamer starts off quelled
 	gaming_withdrawal_timer = addtimer(CALLBACK(src, PROC_REF(enter_withdrawal)), GAMING_WITHDRAWAL_TIME, TIMER_STOPPABLE)
 
diff --git a/code/datums/quirks/positive_quirks.dm b/code/datums/quirks/positive_quirks.dm
index 7e43c0e35b3..a0e29e32d97 100644
--- a/code/datums/quirks/positive_quirks.dm
+++ b/code/datums/quirks/positive_quirks.dm
@@ -17,17 +17,15 @@
 	desc = "You just don't care as much as other people. That's nice to have in a place like this, I guess."
 	icon = "meh"
 	value = 4
-	mood_quirk = TRUE
+	quirk_flags = QUIRK_HUMAN_ONLY|QUIRK_MOODLET_BASED
 	medical_record_text = "Patient was administered the Apathy Evaluation Scale but did not bother to complete it."
 	mail_goodies = list(/obj/item/hourglass)
 
-/datum/quirk/apathetic/add()
-	if (quirk_holder.mob_mood)
-		quirk_holder.mob_mood.mood_modifier -= 0.2
+/datum/quirk/apathetic/add(client/client_source)
+	quirk_holder.mob_mood?.mood_modifier -= 0.2
 
 /datum/quirk/apathetic/remove()
-	if (quirk_holder.mob_mood)
-		quirk_holder.mob_mood.mood_modifier += 0.2
+	quirk_holder.mob_mood?.mood_modifier += 0.2
 
 /datum/quirk/drunkhealing
 	name = "Drunken Resilience"
@@ -37,7 +35,7 @@
 	gain_text = "<span class='notice'>You feel like a drink would do you good.</span>"
 	lose_text = "<span class='danger'>You no longer feel like drinking would ease your pain.</span>"
 	medical_record_text = "Patient has unusually efficient liver metabolism and can slowly regenerate wounds by drinking alcoholic beverages."
-	processing_quirk = TRUE
+	quirk_flags = QUIRK_HUMAN_ONLY|QUIRK_PROCESSES
 	mail_goodies = list(/obj/effect/spawner/random/food_or_drink/booze)
 
 /datum/quirk/drunkhealing/process(delta_time)
@@ -85,10 +83,10 @@
 		/obj/item/toy/figure/clown,
 	)
 
-/datum/quirk/item_quirk/clown_enjoyer/add_unique()
+/datum/quirk/item_quirk/clown_enjoyer/add_unique(client/client_source)
 	give_item_to_holder(/obj/item/clothing/accessory/clown_enjoyer_pin, list(LOCATION_BACKPACK = ITEM_SLOT_BACKPACK, LOCATION_HANDS = ITEM_SLOT_HANDS))
 
-/datum/quirk/item_quirk/clown_enjoyer/add()
+/datum/quirk/item_quirk/clown_enjoyer/add(client/client_source)
 	var/datum/atom_hud/fan = GLOB.huds[DATA_HUD_FAN]
 	fan.show_to(quirk_holder)
 
@@ -115,10 +113,10 @@
 		/obj/item/toy/crayon/spraycan/mimecan,
 	)
 
-/datum/quirk/item_quirk/mime_fan/add_unique()
+/datum/quirk/item_quirk/mime_fan/add_unique(client/client_source)
 	give_item_to_holder(/obj/item/clothing/accessory/mime_fan_pin, list(LOCATION_BACKPACK = ITEM_SLOT_BACKPACK, LOCATION_HANDS = ITEM_SLOT_HANDS))
 
-/datum/quirk/item_quirk/mime_fan/add()
+/datum/quirk/item_quirk/mime_fan/add(client/client_source)
 	var/datum/atom_hud/fan = GLOB.huds[DATA_HUD_FAN]
 	fan.show_to(quirk_holder)
 
@@ -141,7 +139,7 @@
 	mob_trait = TRAIT_FRIENDLY
 	gain_text = "<span class='notice'>You want to hug someone.</span>"
 	lose_text = "<span class='danger'>You no longer feel compelled to hug others.</span>"
-	mood_quirk = TRUE
+	quirk_flags = QUIRK_HUMAN_ONLY|QUIRK_MOODLET_BASED
 	medical_record_text = "Patient demonstrates low-inhibitions for physical contact and well-developed arms. Requesting another doctor take over this case."
 	mail_goodies = list(/obj/item/storage/box/hug)
 
@@ -151,7 +149,7 @@
 	icon = "grin"
 	value = 4
 	mob_trait = TRAIT_JOLLY
-	mood_quirk = TRUE
+	quirk_flags = QUIRK_HUMAN_ONLY|QUIRK_MOODLET_BASED
 	medical_record_text = "Patient demonstrates constant euthymia irregular for environment. It's a bit much, to be honest."
 	mail_goodies = list(/obj/item/clothing/mask/joy)
 
@@ -177,7 +175,7 @@
 	medical_record_text = "Patient brain scans show a highly-developed auditory pathway."
 	mail_goodies = list(/obj/effect/spawner/random/entertainment/musical_instrument, /obj/item/instrument/piano_synth/headphones)
 
-/datum/quirk/item_quirk/musician/add_unique()
+/datum/quirk/item_quirk/musician/add_unique(client/client_source)
 	give_item_to_holder(/obj/item/choice_beacon/music, list(LOCATION_BACKPACK = ITEM_SLOT_BACKPACK, LOCATION_HANDS = ITEM_SLOT_HANDS))
 
 /datum/quirk/night_vision
@@ -195,7 +193,7 @@
 		/obj/item/skillchip/light_remover,
 	)
 
-/datum/quirk/night_vision/add()
+/datum/quirk/night_vision/add(client/client_source)
 	refresh_quirk_holder_eyes()
 
 /datum/quirk/night_vision/remove()
@@ -244,7 +242,7 @@
 		/obj/item/storage/fancy/candle_box,
 	)
 
-/datum/quirk/item_quirk/spiritual/add_unique()
+/datum/quirk/item_quirk/spiritual/add_unique(client/client_source)
 	give_item_to_holder(/obj/item/storage/fancy/candle_box, list(LOCATION_BACKPACK = ITEM_SLOT_BACKPACK, LOCATION_HANDS = ITEM_SLOT_HANDS))
 	give_item_to_holder(/obj/item/storage/box/matches, list(LOCATION_BACKPACK = ITEM_SLOT_BACKPACK, LOCATION_HANDS = ITEM_SLOT_HANDS))
 
@@ -264,7 +262,7 @@
 		/obj/item/canvas/twentythree_twentythree
 	)
 
-/datum/quirk/item_quirk/tagger/add_unique()
+/datum/quirk/item_quirk/tagger/add_unique(client/client_source)
 	give_item_to_holder(/obj/item/toy/crayon/spraycan, list(LOCATION_BACKPACK = ITEM_SLOT_BACKPACK, LOCATION_HANDS = ITEM_SLOT_HANDS))
 
 /datum/quirk/voracious
@@ -282,9 +280,10 @@
 	desc = "You possess excellent communication skills in sign language."
 	icon = "hands"
 	value = 4
+	quirk_flags = QUIRK_HUMAN_ONLY|QUIRK_CHANGES_APPEARANCE
 	mail_goodies = list(/obj/item/clothing/gloves/radio)
 
-/datum/quirk/item_quirk/signer/add_unique()
+/datum/quirk/item_quirk/signer/add_unique(client/client_source)
 	quirk_holder.AddComponent(/datum/component/sign_language)
 	var/obj/item/clothing/gloves/gloves_type = /obj/item/clothing/gloves/radio
 	if(isplasmaman(quirk_holder))
diff --git a/code/modules/client/preferences/heterochromatic.dm b/code/modules/client/preferences/heterochromatic.dm
index 03753a290f5..38d0d646089 100644
--- a/code/modules/client/preferences/heterochromatic.dm
+++ b/code/modules/client/preferences/heterochromatic.dm
@@ -10,6 +10,5 @@
 	return "Heterochromatic" in preferences.all_quirks
 
 /datum/preference/color/heterochromatic/apply_to_human(mob/living/carbon/human/target, value)
-	for(var/datum/quirk/heterochromatic/hetero_quirk in target.quirks)
-		hetero_quirk.color = value
-		hetero_quirk.link_to_holder()
+	var/datum/quirk/heterochromatic/hetero_quirk = locate() in target.quirks
+	hetero_quirk?.apply_heterochromatic_eyes(value)
diff --git a/code/modules/mob/dead/new_player/preferences_setup.dm b/code/modules/mob/dead/new_player/preferences_setup.dm
index 55c7b4fd0dc..a16daec0b31 100644
--- a/code/modules/mob/dead/new_player/preferences_setup.dm
+++ b/code/modules/mob/dead/new_player/preferences_setup.dm
@@ -67,7 +67,7 @@
 			available_hardcore_quirks -= picked_quirk
 			continue
 
-		if(initial(picked_quirk.mood_quirk) && CONFIG_GET(flag/disable_human_mood)) //check for moodlet quirks
+		if((initial(picked_quirk.quirk_flags) & QUIRK_MOODLET_BASED) && CONFIG_GET(flag/disable_human_mood)) //check for moodlet quirks
 			available_hardcore_quirks -= picked_quirk
 			continue
 
@@ -106,5 +106,16 @@
 		mannequin.job = preview_job.title
 		mannequin.dress_up_as_job(preview_job, TRUE)
 
+	// Apply visual quirks
+	// Yes we do it every time because it needs to be done after job gear
+	if(SSquirks?.initialized)
+		// And yes we need to clean all the quirk datums every time
+		mannequin.cleanse_quirk_datums()
+		for(var/quirk_name as anything in all_quirks)
+			var/datum/quirk/quirk_type = SSquirks.quirks[quirk_name]
+			if(!(initial(quirk_type.quirk_flags) & QUIRK_CHANGES_APPEARANCE))
+				continue
+			mannequin.add_quirk(quirk_type, parent)
+
 	return mannequin.appearance
 */
diff --git a/code/modules/mob/living/carbon/human/species_types/jellypeople.dm b/code/modules/mob/living/carbon/human/species_types/jellypeople.dm
index 6d5f65a414e..1522b357421 100644
--- a/code/modules/mob/living/carbon/human/species_types/jellypeople.dm
+++ b/code/modules/mob/living/carbon/human/species_types/jellypeople.dm
@@ -297,7 +297,7 @@
 	var/datum/species/jelly/slime/spare_datum = spare.dna.species
 	spare_datum.bodies = origin_datum.bodies
 
-	H.transfer_trait_datums(spare)
+	H.transfer_quirk_datums(spare)
 	H.mind.transfer_to(spare)
 	spare.visible_message("<span class='warning'>[H] distorts as a new body \
 		\"steps out\" of [H.p_them()].</span>",
@@ -443,7 +443,7 @@
 			span_notice("You stop moving this body..."))
 	else
 		to_chat(M.current, span_notice("You abandon this body..."))
-	M.current.transfer_trait_datums(dupe)
+	M.current.transfer_quirk_datums(dupe)
 	M.transfer_to(dupe)
 	dupe.visible_message("<span class='notice'>[dupe] blinks and looks \
 		around.</span>",
diff --git a/code/modules/mob/living/status_procs.dm b/code/modules/mob/living/status_procs.dm
index c5af051f4ce..216bba9f836 100644
--- a/code/modules/mob/living/status_procs.dm
+++ b/code/modules/mob/living/status_procs.dm
@@ -483,15 +483,24 @@
 			priority_absorb_key["stuns_absorbed"] += amount
 		return TRUE
 
-/mob/living/proc/add_quirk(quirktype) //separate proc due to the way these ones are handled
-	if(HAS_TRAIT(src, quirktype))
-		return
-	var/datum/quirk/quirk = quirktype
-	var/qname = initial(quirk.name)
+/**
+ * Adds the passed quirk to the mob
+ *
+ * Arguments
+ * * quirktype - Quirk typepath to add to the mob
+ * * override_client - optional, allows a client to be passed to the quirks on add procs.
+ * If not passed, defaults to this mob's client.
+ *
+ * Returns TRUE on success, FALSE on failure (already has the quirk, etc)
+ */
+/mob/living/proc/add_quirk(datum/quirk/quirktype, client/override_client)
+	if(has_quirk(quirktype))
+		return FALSE
+	var/qname = initial(quirktype.name)
 	if(!SSquirks || !SSquirks.quirks[qname])
-		return
-	quirk = new quirktype()
-	if(quirk.add_to_holder(src))
+		return FALSE
+	var/datum/quirk/quirk = new quirktype()
+	if(quirk.add_to_holder(new_holder = src, client_source = override_client))
 		return TRUE
 	qdel(quirk)
 	return FALSE
diff --git a/code/modules/mob_spawn/ghost_roles/golem_roles.dm b/code/modules/mob_spawn/ghost_roles/golem_roles.dm
index 64d0280558e..7f703ac88fd 100644
--- a/code/modules/mob_spawn/ghost_roles/golem_roles.dm
+++ b/code/modules/mob_spawn/ghost_roles/golem_roles.dm
@@ -89,7 +89,7 @@
 		H.visible_message(span_notice("A faint light leaves [H], moving to [src] and animating it!"),span_notice("You leave your old body behind, and transfer into [src]!"))
 		show_flavor = FALSE
 		var/mob/living/carbon/human/newgolem = create(newname = H.real_name)
-		H.transfer_trait_datums(newgolem)
+		H.transfer_quirk_datums(newgolem)
 		H.mind.transfer_to(newgolem)
 		H.death()
 		return
diff --git a/modular_skyrat/master_files/code/datums/quirks/negative.dm b/modular_skyrat/master_files/code/datums/quirks/negative.dm
index 6f1cdc11ae9..08599ea2875 100644
--- a/modular_skyrat/master_files/code/datums/quirks/negative.dm
+++ b/modular_skyrat/master_files/code/datums/quirks/negative.dm
@@ -42,17 +42,18 @@
 
 // If brainproblems is added to a synth, this detours to the brainproblems/synth quirk.
 // TODO: Add more brain-specific detours when PR #16105 is merged
-/datum/quirk/item_quirk/brainproblems/add_to_holder(mob/living/new_holder, quirk_transfer)
-	if(!(issynthetic(new_holder) && (src.type == /datum/quirk/item_quirk/brainproblems)))
+/datum/quirk/item_quirk/brainproblems/add_to_holder(mob/living/new_holder, quirk_transfer, client/client_source)
+	if(!issynthetic(new_holder) || type != /datum/quirk/item_quirk/brainproblems)
 		// Defer to TG brainproblems if the character isn't robotic.
 		return ..()
+
 	// TODO: Check brain type and detour to appropriate brainproblems quirk
 	var/datum/quirk/item_quirk/brainproblems/synth/bp_synth = new
 	qdel(src)
-	return bp_synth.add_to_holder(new_holder, quirk_transfer)
+	return bp_synth.add_to_holder(new_holder, quirk_transfer, client_source)
 
 // Synthetics get liquid_solder with Brain Tumor instead of mannitol.
-/datum/quirk/item_quirk/brainproblems/synth/add_unique()
+/datum/quirk/item_quirk/brainproblems/synth/add_unique(client/client_source)
 	give_item_to_holder(
 		/obj/item/storage/pill_bottle/liquid_solder/braintumor,
 		list(
@@ -76,10 +77,11 @@
 	hidden_quirk = TRUE
 
 // If blooddeficiency is added to a synth, this detours to the blooddeficiency/synth quirk.
-/datum/quirk/blooddeficiency/add_to_holder(mob/living/new_holder, quirk_transfer)
-	if(!(issynthetic(new_holder) && (src.type == /datum/quirk/blooddeficiency)))
+/datum/quirk/blooddeficiency/add_to_holder(mob/living/new_holder, quirk_transfer, client/client_source)
+	if(!issynthetic(new_holder) || type != /datum/quirk/blooddeficiency)
 		// Defer to TG blooddeficiency if the character isn't robotic.
 		return ..()
+
 	var/datum/quirk/blooddeficiency/synth/bd_synth = new
 	qdel(src)
 	return bd_synth.add_to_holder(new_holder, quirk_transfer)
diff --git a/modular_skyrat/master_files/code/datums/quirks/neutral.dm b/modular_skyrat/master_files/code/datums/quirks/neutral.dm
index efb84d5e292..ff7f149fa88 100644
--- a/modular_skyrat/master_files/code/datums/quirks/neutral.dm
+++ b/modular_skyrat/master_files/code/datums/quirks/neutral.dm
@@ -1,11 +1,12 @@
 /datum/quirk/equipping
 	abstract_parent_type = /datum/quirk/equipping
+	quirk_flags = QUIRK_HUMAN_ONLY|QUIRK_CHANGES_APPEARANCE
 	/// the items that will be equipped, formatted in the way of [item_path = list of slots it can be equipped to], will not equip over nodrop items
 	var/list/items = list()
 	/// the items that will be forcefully equipped, formatted in the way of [item_path = list of slots it can be equipped to], will equip over nodrop items
 	var/list/forced_items = list()
 
-/datum/quirk/equipping/add_unique()
+/datum/quirk/equipping/add_unique(client/client_source)
 	var/mob/living/carbon/carbon_holder = quirk_holder
 	if (!items || !carbon_holder)
 		return
@@ -56,7 +57,7 @@
 	items = list(/obj/item/clothing/accessory/breathing = list(ITEM_SLOT_BACKPACK))
 	var/breath_type = "oxygen"
 
-/datum/quirk/equipping/lungs/add()
+/datum/quirk/equipping/lungs/add(client/client_source)
 	var/mob/living/carbon/human/carbon_holder = quirk_holder
 	if (!istype(carbon_holder) || !lungs_typepath)
 		return
diff --git a/modular_skyrat/master_files/code/datums/traits/neutral.dm b/modular_skyrat/master_files/code/datums/traits/neutral.dm
index d5571e0b129..2810450f34f 100644
--- a/modular_skyrat/master_files/code/datums/traits/neutral.dm
+++ b/modular_skyrat/master_files/code/datums/traits/neutral.dm
@@ -36,14 +36,27 @@
 	name = "Pseudobulbar Affect"
 	desc = "At random intervals, you suffer uncontrollable bursts of laughter."
 	value = 0
+	quirk_flags = QUIRK_HUMAN_ONLY|QUIRK_PROCESSES
 	medical_record_text = "Patient suffers with sudden and uncontrollable bursts of laughter."
 	var/pcooldown = 0
 	var/pcooldown_time = 60 SECONDS
 	icon = "grin-squint-tears"
 
-/datum/quirk/item_quirk/joker/add_unique()
+/datum/quirk/item_quirk/joker/add_unique(client/client_source)
 	give_item_to_holder(/obj/item/paper/joker, list(LOCATION_BACKPACK = ITEM_SLOT_BACKPACK, LOCATION_HANDS = ITEM_SLOT_HANDS))
 
+/datum/quirk/item_quirk/joker/process()
+	if(pcooldown > world.time)
+		return
+	pcooldown = world.time + pcooldown_time
+	var/mob/living/carbon/human/user = quirk_holder
+	if(user && istype(user))
+		if(user.stat == CONSCIOUS)
+			if(prob(20))
+				user.emote("laugh")
+				addtimer(CALLBACK(user, /mob/proc/emote, "laugh"), 5 SECONDS)
+				addtimer(CALLBACK(user, /mob/proc/emote, "laugh"), 10 SECONDS)
+
 /obj/item/paper/joker
 	name = "disability card"
 	icon = 'modular_skyrat/master_files/icons/obj/card.dmi'
@@ -153,18 +166,6 @@
 
 	balloon_alert(user, "card flipped")
 
-/datum/quirk/item_quirk/joker/process()
-	if(pcooldown > world.time)
-		return
-	pcooldown = world.time + pcooldown_time
-	var/mob/living/carbon/human/user = quirk_holder
-	if(user && istype(user))
-		if(user.stat == CONSCIOUS)
-			if(prob(20))
-				user.emote("laugh")
-				addtimer(CALLBACK(user, /mob/proc/emote, "laugh"), 5 SECONDS)
-				addtimer(CALLBACK(user, /mob/proc/emote, "laugh"), 10 SECONDS)
-
 /datum/quirk/feline_aspect
 	name = "Feline Traits"
 	desc = "You happen to act like a feline, for whatever reason."
@@ -181,7 +182,7 @@
 	value = 0
 	medical_record_text = "Patient was seen digging through the trash can. Keep an eye on them."
 
-/datum/quirk/item_quirk/canine/add_unique()
+/datum/quirk/item_quirk/canine/add_unique(client/client_source)
 	var/mob/living/carbon/human/human_holder = quirk_holder
 	var/obj/item/organ/internal/tongue/old_tongue = human_holder.getorganslot(ORGAN_SLOT_TONGUE)
 	old_tongue.Remove(human_holder)
diff --git a/modular_skyrat/modules/hydra/code/neutral.dm b/modular_skyrat/modules/hydra/code/neutral.dm
index 6da99e20ecb..7187c550fec 100644
--- a/modular_skyrat/modules/hydra/code/neutral.dm
+++ b/modular_skyrat/modules/hydra/code/neutral.dm
@@ -8,7 +8,7 @@
 	medical_record_text = "There are multiple heads and personalities affixed to one body."
 	icon = "horse-head"
 
-/datum/quirk/hydra/add()
+/datum/quirk/hydra/add(client/client_source)
 	var/mob/living/carbon/human/hydra = quirk_holder
 	var/datum/action/innate/hydra/spell = new
 	var/datum/action/innate/hydrareset/resetspell = new
diff --git a/modular_skyrat/modules/oversized/code/oversized_quirk.dm b/modular_skyrat/modules/oversized/code/oversized_quirk.dm
index 195b5c0222f..cf1dc995c39 100644
--- a/modular_skyrat/modules/oversized/code/oversized_quirk.dm
+++ b/modular_skyrat/modules/oversized/code/oversized_quirk.dm
@@ -13,8 +13,9 @@
 	mob_trait = TRAIT_OVERSIZED
 	icon = "expand-arrows-alt"
 	veteran_only = TRUE
+	quirk_flags = QUIRK_HUMAN_ONLY|QUIRK_CHANGES_APPEARANCE
 
-/datum/quirk/oversized/add()
+/datum/quirk/oversized/add(client/client_source)
 	var/mob/living/carbon/human/human_holder = quirk_holder
 	human_holder.dna.features["body_size"] = 2
 	human_holder.maptext_height = 32 * human_holder.dna.features["body_size"] //Adjust runechat height
diff --git a/tgstation.dme b/tgstation.dme
index 30b368280f6..b9767fd0f49 100644
--- a/tgstation.dme
+++ b/tgstation.dme
@@ -157,6 +157,7 @@
 #include "code\__DEFINES\profile.dm"
 #include "code\__DEFINES\projectiles.dm"
 #include "code\__DEFINES\qdel.dm"
+#include "code\__DEFINES\quirks.dm"
 #include "code\__DEFINES\radiation.dm"
 #include "code\__DEFINES\radio.dm"
 #include "code\__DEFINES\reactions.dm"