Oxygen is Toxic to the Vox, Plasma Heals Plasmamen, Plasmaman Suit Autoextinguishes, Oxygen Burns Plasmamen

Oxygen is toxic to the Vox (as toxic as plasma).
Plasma healing plasmaman from swindly @
https://github.com/tgstation/tgstation/pull/24209
Plasmaman suit auto-extinguishing actually does something now.
Oxygen burns Plasmamen.

code/__DEFINES/flags.dm

@@ -23,6 +23,7 @@
 
 #define BLOCK_GAS_SMOKE_EFFECT	8192	// blocks the effect that chemical clouds would have on a mob --glasses, mask and helmets ONLY!
 #define THICKMATERIAL 			8192	//prevents syringes, parapens and hypos if the external suit or helmet (if targeting head) has this flag. Example: space suits, biosuit, bombsuits, thick suits that cover your body. (NOTE: flag shared with BLOCK_GAS_SMOKE_EFFECT)
+#define AUTOEXTINGUISH			16384	// Suits that have this will automatically extinguish a burning mob when worn.
 
 //Reagent flags
 #define REAGENT_NOREACT			1
@@ -43,6 +44,7 @@
 #define ALL_RPARTS		2048
 #define NOGUNS			4096
 #define NOTRANSSTING	8192
+#define PLASMA_BASED	16384
 
 //Species clothing flags
 #define HAS_UNDERWEAR 	1

code/modules/clothing/clothing.dm

@@ -497,6 +497,11 @@ BLIND     // can't see anything
 	else
 		to_chat(user, "<span class='notice'>You attempt to button up the velcro on \the [src], before promptly realising how retarded you are.</span>")
 
+/obj/item/clothing/suit/proc/auto_extinguish(var/mob/living/carbon/human/user)
+	if(istype(user))
+		to_chat(user, "<span class='warning'>You hear a soft click and a hiss from your suit as it automatically extinguishes the fire.</span>")
+		user.ExtinguishMob()
+
 /obj/item/clothing/suit/equipped(var/mob/living/carbon/human/user, var/slot) //Handle tail-hiding on a by-species basis.
 	..()
 	if(ishuman(user) && hide_tail_by_species && slot == slot_wear_suit)

code/modules/clothing/spacesuits/plasmamen.dm

@@ -11,7 +11,7 @@
 	flags_inv = HIDEGLOVES|HIDESHOES
 	max_heat_protection_temperature = SPACE_SUIT_MAX_TEMP_PROTECT
 	species_restricted = list("Plasmaman")
-	flags = STOPSPRESSUREDMAGE
+	flags = STOPSPRESSUREDMAGE | AUTOEXTINGUISH
 
 	icon_state = "plasmaman_suit"
 	item_state = "plasmaman_suit"
@@ -24,16 +24,14 @@
 	..(user)
 	to_chat(user, "<span class='info'>There are [extinguishes_left] extinguisher canisters left in this suit.</span>")
 
-/obj/item/clothing/suit/space/eva/plasmaman/proc/Extinguish(var/mob/user)
-	var/mob/living/carbon/human/H=user
-	if(extinguishes_left)
+/obj/item/clothing/suit/space/eva/plasmaman/auto_extinguish(var/mob/living/carbon/human/H)
+	if(istype(H) && extinguishes_left)
 		if(next_extinguish > world.time)
 			return
 
 		next_extinguish = world.time + extinguish_cooldown
 		extinguishes_left--
-		to_chat(H, "<span class='warning'>Your suit automatically extinguishes the fire.</span>")
-		H.ExtinguishMob()
+		..()
 
 /obj/item/clothing/head/helmet/space/eva/plasmaman
 	name = "plasmaman helmet"

code/modules/mob/living/carbon/human/life.dm

@@ -485,6 +485,8 @@
 	if(on_fire)
 		var/thermal_protection = get_thermal_protection()
 
+		if(wear_suit && wear_suit.flags & AUTOEXTINGUISH)
+			wear_suit.auto_extinguish(src)
 		if(thermal_protection >= FIRE_IMMUNITY_SUIT_MAX_TEMP_PROTECT)
 			return
 		if(thermal_protection >= FIRE_SUIT_MAX_TEMP_PROTECT)

code/modules/mob/living/carbon/human/species/plasmaman.dm

@@ -6,7 +6,7 @@
 	//language = "Clatter"
 	unarmed_type = /datum/unarmed_attack/punch
 
-	flags = IS_WHITELISTED | NO_BLOOD | NOTRANSSTING
+	flags = IS_WHITELISTED | NO_BLOOD | NOTRANSSTING | PLASMA_BASED
 	dietflags = DIET_OMNI
 	reagent_tag = PROCESS_ORG
 
@@ -15,6 +15,7 @@
 	butt_sprite = "plasma"
 
 	breath_type = "plasma"
+	poison_type = null
 
 	heat_level_1 = 350  // Heat damage level 1 above this point.
 	heat_level_2 = 400  // Heat damage level 2 above this point.

code/modules/reagents/chemistry/reagents/misc.dm

@@ -39,6 +39,25 @@
 	reagent_state = GAS
 	color = "#808080" // rgb: 128, 128, 128
 
+/datum/reagent/oxygen/on_mob_life(var/mob/living/carbon/human/H)
+	if(istype(H) && H.species && H.species.poison_type && H.species.poison_type == id)
+		H.adjustToxLoss(1*REAGENTS_EFFECT_MULTIPLIER) //Same as plasma.
+	if(istype(H) && H.species && H.species.flags & PLASMA_BASED) //Oxygen lights up plasma-based lifeforms.
+		if(prob(60))
+			H.adjust_fire_stacks(0.25)
+		if(prob(40))
+			H.IgniteMob() //Light them up.
+	..()
+
+/datum/reagent/oxygen/reaction_mob(var/mob/living/carbon/human/H, method=TOUCH, volume)
+	if(istype(H) && H.species && H.species.flags & PLASMA_BASED) //Oxygen lights up plasma-based lifeforms.
+		if(method == INGEST)
+			to_chat(H, "<span class='warning'>You feel a horrible burning from within as your body bursts into flame!</span>")
+		if(method == TOUCH)
+			to_chat(H, "<span class='warning'>Your body bursts into flames as it comes into contact with the substance!</span>")
+		H.adjust_fire_stacks(1) //Same as phlogiston, guaranteed one-time firestack delivery and ignition.
+		H.IgniteMob()
+	..()
 
 /datum/reagent/nitrogen
 	name = "Nitrogen"

code/modules/reagents/chemistry/reagents/pyrotechnic.dm

@@ -22,7 +22,12 @@
 	color = "#7A2B94"
 
 /datum/reagent/plasma/on_mob_life(mob/living/M)
-	M.adjustToxLoss(1*REAGENTS_EFFECT_MULTIPLIER)
+	var/mob/living/carbon/human/H = M
+	if(istype(H) && H.species && H.species.flags & PLASMA_BASED) //Plasma shouldn't poison plasmamen.
+		if(prob(20))
+			H.heal_organ_damage(1, 1)
+	else
+		M.adjustToxLoss(1*REAGENTS_EFFECT_MULTIPLIER)
 	if(holder.has_reagent("epinephrine"))
 		holder.remove_reagent("epinephrine", 2)
 	if(iscarbon(M))