Planescape: Torment
A massive war between the Baatezu and the Tanar'ri. It rages in the Lower Planes, but every plane is touched by it. It is an ideological war seeking to define evil - evil of the horde, a mob mentality of whirling evil, killing and plundering, or the strictly regimented evil of exploitation.
It gives research a prod, producing more horrific creations.
Part of Fhjull's assignment was drafting new recruits, mostly planar warriors and mages from other worlds to serve as fodder.
(Fhjull Forked-Tongue)