diff --git a/_maps/RandomRuins/SpaceRuins/shuttlerelic.dmm b/_maps/RandomRuins/SpaceRuins/shuttlerelic.dmm
index 2d8e721f93e..ff04fe2c4eb 100644
--- a/_maps/RandomRuins/SpaceRuins/shuttlerelic.dmm
+++ b/_maps/RandomRuins/SpaceRuins/shuttlerelic.dmm
@@ -33,7 +33,8 @@
 "i" = (
 /obj/structure/closet{
 	icon_state = "oldcloset";
-	name = "strange closet"
+	name = "strange closet";
+	enable_door_overlay = 0
 	},
 /turf/open/floor/oldshuttle,
 /area/ruin/powered)
diff --git a/code/controllers/subsystem/overlays.dm b/code/controllers/subsystem/overlays.dm
index 7e36b865df1..e99fe9e912b 100644
--- a/code/controllers/subsystem/overlays.dm
+++ b/code/controllers/subsystem/overlays.dm
@@ -64,7 +64,7 @@ SUBSYSTEM_DEF(overlays)
 	stringbro.icon = icon
 	stringbro.icon_state = iconstate
 	return stringbro.appearance
-	
+
 /proc/icon2appearance(icon)
 	var/static/image/iconbro = new()
 	iconbro.icon = icon
@@ -79,6 +79,14 @@ SUBSYSTEM_DEF(overlays)
 		if(!overlay)
 			continue
 		if (istext(overlay))
+#ifdef UNIT_TESTS
+			// This is too expensive to run normally but running it during CI is a good test
+			var/list/icon_states_available = icon_states(icon)
+			if(!(overlay in icon_states_available))
+				var/icon_file = "[icon]" || "Unknown Generated Icon"
+				stack_trace("Invalid overlay: Icon object '[icon_file]' [REF(icon)] used in '[src]' [type] is missing icon state [overlay].")
+				continue
+#endif
 			new_overlays += iconstate2appearance(icon, overlay)
 		else if(isicon(overlay))
 			new_overlays += icon2appearance(overlay)
diff --git a/code/game/machinery/computer/camera.dm b/code/game/machinery/computer/camera.dm
index a3423724680..da0bbdc2a3f 100644
--- a/code/game/machinery/computer/camera.dm
+++ b/code/game/machinery/computer/camera.dm
@@ -252,6 +252,7 @@
 	desc = "Used for watching an empty arena."
 	icon = 'icons/obj/stationobjs.dmi'
 	icon_state = "telescreen"
+	icon_keyboard = null
 	layer = SIGN_LAYER
 	network = list("thunder")
 	density = FALSE
diff --git a/code/game/machinery/cryopod.dm b/code/game/machinery/cryopod.dm
index 146a2372eb9..44becda2de4 100644
--- a/code/game/machinery/cryopod.dm
+++ b/code/game/machinery/cryopod.dm
@@ -16,6 +16,7 @@ GLOBAL_LIST_EMPTY(cryopod_computers)
 	desc = "An interface between crew and the cryogenic storage oversight systems."
 	icon = 'modular_skyrat/modules/cryosleep/icons/cryogenics.dmi' //SKYRAT EDIT CHANGE - ORIGINAL: 'icons/obj/machines/cryopod.dmi'
 	icon_state = "cellconsole_1"
+	icon_keyboard = null
 	// circuit = /obj/item/circuitboard/cryopodcontrol
 	density = FALSE
 	interaction_flags_machine = INTERACT_MACHINE_OFFLINE
diff --git a/code/game/objects/items/RCD.dm b/code/game/objects/items/RCD.dm
index 9f0693df664..a33edea27d2 100644
--- a/code/game/objects/items/RCD.dm
+++ b/code/game/objects/items/RCD.dm
@@ -765,7 +765,8 @@ GLOBAL_VAR_INIT(icon_holographic_window, init_holographic_window())
 	. = ..()
 	if(has_ammobar)
 		var/ratio = CEILING((matter / max_matter) * ammo_sections, 1)
-		. += "[icon_state]_charge[ratio]"
+		if(ratio > 0)
+			. += "[icon_state]_charge[ratio]"
 
 /obj/item/construction/rcd/Initialize()
 	. = ..()
diff --git a/code/game/objects/items/defib.dm b/code/game/objects/items/defib.dm
index 7defed9e935..b2b38a54261 100644
--- a/code/game/objects/items/defib.dm
+++ b/code/game/objects/items/defib.dm
@@ -26,6 +26,16 @@
 	var/obj/item/stock_parts/cell/high/cell
 	var/combat = FALSE //if true, revive through hardsuits, allow for combat shocking
 	var/cooldown_duration = 5 SECONDS//how long does it take to recharge
+	/// The icon state for the paddle overlay, not applied if null
+	var/paddle_state = "defibunit-paddles"
+	/// The icon state for the powered on overlay, not applied if null
+	var/powered_state = "defibunit-powered"
+	/// The icon state for the charge bar overlay, not applied if null
+	var/charge_state = "defibunit-charge"
+	/// The icon state for the missing cell overlay, not applied if null
+	var/nocell_state = "defibunit-nocell"
+	/// The icon state for the emagged overlay, not applied if null
+	var/emagged_state = "defibunit-emagged"
 
 /obj/item/defibrillator/get_cell()
 	return cell
@@ -74,18 +84,18 @@
 /obj/item/defibrillator/update_overlays()
 	. = ..()
 
-	if(!on)
-		. += "[initial(icon_state)]-paddles"
-	if(powered)
-		. += "[initial(icon_state)]-powered"
-		if(!QDELETED(cell))
+	if(!on && paddle_state)
+		. += paddle_state
+	if(powered && powered_state)
+		. += powered_state
+		if(!QDELETED(cell) && charge_state)
 			var/ratio = cell.charge / cell.maxcharge
 			ratio = CEILING(ratio*4, 1) * 25
-			. += "[initial(icon_state)]-charge[ratio]"
-	if(!cell)
-		. += "[initial(icon_state)]-nocell"
-	if(!safety)
-		. += "[initial(icon_state)]-emagged"
+			. += "[charge_state][ratio]"
+	if(!cell && nocell_state)
+		. += "[nocell_state]"
+	if(!safety && emagged_state)
+		. += emagged_state
 
 /obj/item/defibrillator/CheckParts(list/parts_list)
 	..()
@@ -257,6 +267,11 @@
 	worn_icon_state = "defibcompact"
 	w_class = WEIGHT_CLASS_NORMAL
 	slot_flags = ITEM_SLOT_BELT
+	paddle_state = "defibcompact-paddles"
+	powered_state = "defibcompact-powered"
+	charge_state = "defibcompact-charge"
+	nocell_state = "defibcompact-nocell"
+	emagged_state = "defibcompact-emagged"
 
 /obj/item/defibrillator/compact/item_action_slot_check(slot, mob/user)
 	if(slot == user.getBeltSlot())
@@ -277,6 +292,9 @@
 	safety = FALSE
 	cooldown_duration = 2.5 SECONDS
 	paddle_type = /obj/item/shockpaddles/syndicate
+	paddle_state = "defibcombat-paddles"
+	powered_state = null
+	emagged_state = null
 
 /obj/item/defibrillator/compact/combat/loaded/Initialize()
 	. = ..()
@@ -295,6 +313,7 @@
 	inhand_icon_state = "defibnt"
 	worn_icon_state = "defibnt"
 	paddle_type = /obj/item/shockpaddles/syndicate/nanotrasen
+	paddle_state = "defibnt-paddles"
 
 //paddles
 
diff --git a/code/game/objects/items/storage/boxes.dm b/code/game/objects/items/storage/boxes.dm
index ebf77b222aa..5d0b4f12e58 100644
--- a/code/game/objects/items/storage/boxes.dm
+++ b/code/game/objects/items/storage/boxes.dm
@@ -714,6 +714,7 @@
 	pickup_sound =  'sound/items/handling/matchbox_pickup.ogg'
 	custom_price = PAYCHECK_ASSISTANT * 0.4
 	base_icon_state = "matchbox"
+	illustration = null
 
 /obj/item/storage/box/matches/ComponentInitialize()
 	. = ..()
diff --git a/code/game/objects/structures/crates_lockers/closets.dm b/code/game/objects/structures/crates_lockers/closets.dm
index 33cef809950..deeb48bcdcf 100644
--- a/code/game/objects/structures/crates_lockers/closets.dm
+++ b/code/game/objects/structures/crates_lockers/closets.dm
@@ -12,6 +12,10 @@
 	armor = list(MELEE = 20, BULLET = 10, LASER = 10, ENERGY = 0, BOMB = 10, BIO = 0, RAD = 0, FIRE = 70, ACID = 60)
 	blocks_emissive = EMISSIVE_BLOCK_UNIQUE
 
+	/// Controls whether a door overlay should be applied using the icon_door value as the icon state
+	var/enable_door_overlay = TRUE
+	var/has_opened_overlay = TRUE
+	var/has_closed_overlay = TRUE
 	var/icon_door = null
 	var/icon_door_override = FALSE //override to have open overlay use icon different to its base's
 	var/secure = FALSE //secure locker or not, also used if overriding a non-secure locker with a secure door overlay to add fancy lights
@@ -80,14 +84,18 @@
 
 /obj/structure/closet/proc/closet_update_overlays(list/new_overlays)
 	. = new_overlays
+	if(enable_door_overlay)
+		if(opened && has_opened_overlay)
+			. += "[icon_door_override ? icon_door : icon_state]_open"
+			var/mutable_appearance/door_blocker = mutable_appearance(icon, "[icon_door || icon_state]_open", plane = EMISSIVE_PLANE)
+			door_blocker.color = GLOB.em_block_color
+			. += door_blocker // If we don't do this the door doesn't block emissives and it looks weird.
+		else if(has_closed_overlay)
+			. += "[icon_door || icon_state]_door"
+
 	if(opened)
-		. += "[icon_door_override ? icon_door : icon_state]_open"
-		var/mutable_appearance/door_blocker = mutable_appearance(icon, "[icon_door || icon_state]_open", plane = EMISSIVE_PLANE)
-		door_blocker.color = GLOB.em_block_color
-		. += door_blocker // If we don't do this the door doesn't block emissives and it looks weird.
 		return
 
-	. += mutable_appearance(icon, "[icon_door || icon_state]_door")
 	if(welded)
 		. += icon_welded
 
diff --git a/code/game/objects/structures/crates_lockers/closets/bodybag.dm b/code/game/objects/structures/crates_lockers/closets/bodybag.dm
index a738699b026..876c1ea81bc 100644
--- a/code/game/objects/structures/crates_lockers/closets/bodybag.dm
+++ b/code/game/objects/structures/crates_lockers/closets/bodybag.dm
@@ -16,6 +16,7 @@
 	anchorable = FALSE
 	mouse_drag_pointer = MOUSE_ACTIVE_POINTER
 	drag_slowdown = 0
+	has_closed_overlay = FALSE
 	var/foldedbag_path = /obj/item/bodybag
 	var/obj/item/bodybag/foldedbag_instance = null
 	var/tagged = FALSE // so closet code knows to put the tag overlay back
diff --git a/code/game/objects/structures/crates_lockers/closets/cardboardbox.dm b/code/game/objects/structures/crates_lockers/closets/cardboardbox.dm
index 2c38cbeeb21..1ecf762c69e 100644
--- a/code/game/objects/structures/crates_lockers/closets/cardboardbox.dm
+++ b/code/game/objects/structures/crates_lockers/closets/cardboardbox.dm
@@ -16,6 +16,7 @@
 	close_sound = 'sound/machines/cardboard_box.ogg'
 	open_sound_volume = 35
 	close_sound_volume = 35
+	enable_door_overlay = FALSE
 	var/move_speed_multiplier = 1
 	var/move_delay = FALSE
 	var/egged = 0
diff --git a/code/game/objects/structures/showcase.dm b/code/game/objects/structures/showcase.dm
index 7172c8ddfb8..a817dff093d 100644
--- a/code/game/objects/structures/showcase.dm
+++ b/code/game/objects/structures/showcase.dm
@@ -28,10 +28,10 @@
 	icon = 'icons/obj/computer.dmi'
 	icon_state = "computer"
 
-/obj/structure/showcase/fakesec/Initialize()
+/obj/structure/showcase/fakesec/update_overlays()
 	. = ..()
-	add_overlay("security")
-	add_overlay("security_key")
+	. += "security"
+	. += "security_key"
 
 /obj/structure/showcase/horrific_experiment
 	name = "horrific experiment"
diff --git a/code/modules/antagonists/abductor/machinery/camera.dm b/code/modules/antagonists/abductor/machinery/camera.dm
index 6c14c277b72..252d2dceabc 100644
--- a/code/modules/antagonists/abductor/machinery/camera.dm
+++ b/code/modules/antagonists/abductor/machinery/camera.dm
@@ -13,6 +13,7 @@
 
 	icon = 'icons/obj/abductor.dmi'
 	icon_state = "camera"
+	icon_keyboard = null
 	resistance_flags = INDESTRUCTIBLE | LAVA_PROOF | FIRE_PROOF | ACID_PROOF
 
 /obj/machinery/computer/camera_advanced/abductor/CreateEye()
diff --git a/code/modules/food_and_drinks/drinks/drinks/bottle.dm b/code/modules/food_and_drinks/drinks/drinks/bottle.dm
index b1ea07b9380..cb3ea7e37dd 100644
--- a/code/modules/food_and_drinks/drinks/drinks/bottle.dm
+++ b/code/modules/food_and_drinks/drinks/drinks/bottle.dm
@@ -24,10 +24,6 @@
 	///Directly relates to the 'knockdown' duration. Lowered by armor (i.e. helmets)
 	var/bottle_knockdown_duration = 1.3 SECONDS
 
-/obj/item/reagent_containers/food/drinks/bottle/update_overlays()
-	. = ..()
-	. += "[initial(icon_state)]shine"
-
 /obj/item/reagent_containers/food/drinks/bottle/small
 	name = "small glass bottle"
 	desc = "This blank bottle is unyieldingly anonymous, offering no clues to its contents."
diff --git a/code/modules/mining/aux_base.dm b/code/modules/mining/aux_base.dm
index c7adb9851e7..dce4174b11d 100644
--- a/code/modules/mining/aux_base.dm
+++ b/code/modules/mining/aux_base.dm
@@ -16,6 +16,7 @@
 	interface with the mining shuttle at the landing site if a mobile beacon is also deployed."
 	icon = 'icons/obj/terminals.dmi'
 	icon_state = "dorm_available"
+	icon_keyboard = null
 	req_one_access = list(ACCESS_AUX_BASE, ACCESS_HEADS)
 	circuit = /obj/item/circuitboard/computer/auxiliary_base
 	/// Shuttle ID of the base
diff --git a/code/modules/mob/living/simple_animal/hostile/megafauna/colossus.dm b/code/modules/mob/living/simple_animal/hostile/megafauna/colossus.dm
index 87c54a8686e..7118ad54089 100644
--- a/code/modules/mob/living/simple_animal/hostile/megafauna/colossus.dm
+++ b/code/modules/mob/living/simple_animal/hostile/megafauna/colossus.dm
@@ -747,6 +747,7 @@ SKYRAT REMOVAL EDIT END*/
 	name = "quantum entanglement stasis warp field"
 	desc = "You can hardly comprehend this thing... which is why you can't see it."
 	icon_state = null //This shouldn't even be visible, so if it DOES show up, at least nobody will notice
+	enable_door_overlay = FALSE //For obvious reasons
 	density = TRUE
 	anchored = TRUE
 	resistance_flags = FIRE_PROOF | ACID_PROOF | INDESTRUCTIBLE
diff --git a/code/modules/projectiles/guns/ballistic/toy.dm b/code/modules/projectiles/guns/ballistic/toy.dm
index 192ee873800..48fd614fe49 100644
--- a/code/modules/projectiles/guns/ballistic/toy.dm
+++ b/code/modules/projectiles/guns/ballistic/toy.dm
@@ -66,6 +66,7 @@
 	fire_sound = 'sound/items/syringeproj.ogg'
 	slot_flags = ITEM_SLOT_BELT
 	w_class = WEIGHT_CLASS_SMALL
+	gun_flags = NONE
 
 /obj/item/gun/ballistic/automatic/c20r/toy //This is the syndicate variant with syndicate firing pin and riot darts.
 	name = "donksoft SMG"
diff --git a/code/modules/projectiles/guns/energy/energy_gun.dm b/code/modules/projectiles/guns/energy/energy_gun.dm
index 5ac35a2d0f1..988377485f9 100644
--- a/code/modules/projectiles/guns/energy/energy_gun.dm
+++ b/code/modules/projectiles/guns/energy/energy_gun.dm
@@ -5,7 +5,7 @@
 	w_class = WEIGHT_CLASS_BULKY
 	inhand_icon_state = null //so the human update icon uses the icon_state instead.
 	ammo_type = list(/obj/item/ammo_casing/energy/disabler, /obj/item/ammo_casing/energy/laser)
-	modifystate = 1
+	modifystate = TRUE
 	can_flashlight = TRUE
 	ammo_x_offset = 3
 	flight_x_offset = 15
@@ -71,6 +71,7 @@
 	righthand_file = 'icons/mob/inhands/weapons/guns_righthand.dmi'
 	cell_type = /obj/item/stock_parts/cell //SKYRAT EDIT ADDITION - GUNSGALORE
 	ammo_type = list(/obj/item/ammo_casing/energy/net, /obj/item/ammo_casing/energy/trap)
+	modifystate = FALSE
 	w_class = WEIGHT_CLASS_NORMAL
 	can_flashlight = FALSE
 	ammo_x_offset = 1
diff --git a/code/modules/reagents/chemistry/machinery/pandemic.dm b/code/modules/reagents/chemistry/machinery/pandemic.dm
index 0bf770954b0..2839404720f 100644
--- a/code/modules/reagents/chemistry/machinery/pandemic.dm
+++ b/code/modules/reagents/chemistry/machinery/pandemic.dm
@@ -7,6 +7,7 @@
 	density = TRUE
 	icon = 'icons/obj/chemical.dmi'
 	icon_state = "mixer0"
+	icon_keyboard = null
 	base_icon_state = "mixer"
 	use_power = TRUE
 	idle_power_usage = 20
diff --git a/code/modules/research/nanites/nanite_cloud_controller.dm b/code/modules/research/nanites/nanite_cloud_controller.dm
index 4579239f6b6..fcfe181c607 100644
--- a/code/modules/research/nanites/nanite_cloud_controller.dm
+++ b/code/modules/research/nanites/nanite_cloud_controller.dm
@@ -5,6 +5,7 @@
 	icon_state = "nanite_cloud_controller"
 	circuit = /obj/item/circuitboard/computer/nanite_cloud_controller
 	icon_screen = "nanite_cloud_controller_screen"
+	icon_keyboard = null
 
 	var/obj/item/disk/nanite_program/disk
 	var/list/datum/nanite_cloud_backup/cloud_backups = list()
diff --git a/code/modules/shuttle/syndicate.dm b/code/modules/shuttle/syndicate.dm
index 94902141ebc..11548ad16de 100644
--- a/code/modules/shuttle/syndicate.dm
+++ b/code/modules/shuttle/syndicate.dm
@@ -39,6 +39,7 @@
 	desc = "Controls the drop pod's launch system."
 	icon = 'icons/obj/terminals.dmi'
 	icon_state = "dorm_available"
+	icon_keyboard = null
 	light_color = LIGHT_COLOR_BLUE
 	req_access = list(ACCESS_SYNDICATE)
 	shuttleId = "steel_rain"
diff --git a/icons/obj/defib.dmi b/icons/obj/defib.dmi
index 68a1f232114..c376cb5f902 100644
Binary files a/icons/obj/defib.dmi and b/icons/obj/defib.dmi differ
diff --git a/icons/obj/guns/energy.dmi b/icons/obj/guns/energy.dmi
index 7f5a11ee167..2549e2adbc9 100644
Binary files a/icons/obj/guns/energy.dmi and b/icons/obj/guns/energy.dmi differ