Yeah, Blight can be really nasty, since it can easily deal 100 damage and poison you. The worst part about the hordes, though, is that there's a 50/50 chance that they get a first strike (since they're special battles, you don't get that luxury), which can immediately put you at a disadvantage that is difficult to overcome.
David is thankfully a bit simpler than that, but his damage output can be pretty scary. He managed to kill two of my party members, but thankfully, he didn't kill the one that also had Zio, so we ping-ponged back and forth with that spell and were able to avoid damage since he kept missing that other demon. He went down after about 6 or 7 turns.
