OK, take that back, Threshold is absolutely the worst dungeon in this game. It's like 4 or 5 boss-level trashmobs of demons that you have to do in a row without the ability to rest, and each mob is harder than any of the previous bosses I've faced in the game by a mile.
I crawled to Vile Devastater, and I've even taken him down on my second try, but I'm raped by the locust things after as my party is all out of spells and buffs and I obviously didn't prepare going in. Honestly, I'm dreading it, but I might need to redo the whole level. chapter 5 was so easy that I thought I could bring whoever I wanted for funsies, but I have Nenio, Demon Archer Lady (forget her name), Soseil, Ulbriq, Seelah, and my mc Demonslayer. Might need a few more Guarded Hearths. Either that, or rerun the level and not let Soseil die as the monsters are easy to kite back to a single guarded hearth, but I stupidly let Soseil die as I thought, "there couldn't possibly be 3 more massive mobs with no rest, right?"
Honestly, I was really loving this game, but Owlcat seemingly has to shit the bed on the landing. This shit's just annoying. I do have about 2.5 million dollars, though, if anyone wants to recommend a few mercs.