The one prior use of War Crime, in which an Operatic warlord left 200 mantid mercenaries paralyzed and burning for two weeks.
The AI offers this as the only time War Crime has ever been used in Dungeon Crawler World. An Operatic Collective warlord combined Fireball and Paralysis against a group of charging soldiers from a mantid team — not creative, but it worked. Parked atop a circle of power at the time, he cast it in a wide arc that hit approximately 200 mercenaries fighting for The Mantids at once. There was only one true mantis in the bunch, and she noped out of the game entirely by ejecting about ten seconds after being hit.
The victims were paralyzed permanently, set on fire permanently, and blown off in an arc away from the caster, not stopping until they hit something — for some, very far indeed. They remained there, paralyzed, burning, and undying for the remainder of the floor, while the caster received an experience point update for every hour or so of their suffering. The AI in charge of that season eventually put the burning NPC mercenaries out of their misery when the floor collapsed some two weeks later, an act the current AI describes as wussy. The warlord who cast it supposedly required an identity reset after the crawl was re-absorbed, and part of his essence eventually formed into the Warlord Hortense Leadership Unit.
The cautionary precedent that convinces Carl of War Crime's horror.