Fixes #9913

Also axes hidden var in lieu of using implants like other foreign objects. Now instead of one object, amount of stuff you can put in someone's organ is restricted by stuff's combined w_class.

code/modules/mob/living/silicon/pai/pai.dm

@@ -281,8 +281,9 @@
 		if(ishuman(holder))
 			var/mob/living/carbon/human/H = holder
 			for(var/obj/item/organ/external/affecting in H.organs)
-				if(affecting.hidden == card)
+				if(card in affecting.implants)
 					affecting.take_damage(rand(30,50))
+					affecting.implants -= card
 					H.visible_message("<span class='danger'>\The [src] explodes out of \the [H]'s [affecting.name] in shower of gore!</span>")
 					break
 		holder.drop_from_inventory(card)