[Wish]

play abysia, who will laugh at the fire.

or... the demons, despite being semi immortal have low low protection, and all you need is magic weapons to rip them apart. caelum comes to mind, for ice weapons that can easily hit the spirit form of the oni. so what you do is have a horde of caelum archers turning them into spirits, followed by ice blade wielding guys (situate towards the back to avoid their fire, and they fly so a hold and attack will put them right where you want them fairly quickly.

I love yomi as well, but mostly because they have a recruitable SC chasis, who, with earth boots or a little empowerment, can cast invulnerability and soul vortex on themselves. (and bless themselves) before jumping into hand to hand.

though lanka's mandaha blood summons are much better chasis, they can't invuln themselves, but they can cloud trapeze, mirror image, and mistform themselves before jumping into combat. so a little armor goes a long way with those guys. I guess thats more a late game strat though.