[rdonj]

In elaboration. Yomi has, as tifone said, fire and poison tossing troops (though I probably wouldn't rely on these), cheap archers and access to flaming arrows. They also have cheap, highly massable stealthy units to raid with.

They also have cold resistant multi-form blockers that turn ethereal when they die and do large amounts of damage, the earth mages to cast armor of achilles, destruction, earth meld etc, and to cast strength of giants. If you go the alteration route you also get blight, which they can natively cast, that you can use to increase unrest in their capital and kill off some of their population. In short yomi has access to pretty much every method I've heard mentioned that's helpful for killing niefel giants. If it's later in the game it's almost just better for you because you'll be able to combine more of the above methods, and maybe even add in weapons of sharpness.

Pretty much the only thing they don't have is cold immune thugs, unless you research conjuration for the ghost generals or trade for some rings. If you can manage to get cold immune oni generals/dai oni, you can spam hand of death at them.

Anyway this is all theorycrafting since I've never actually done it in practice, but I'm pretty sure it would work.