Funny enough, I finally got it shortly after venting here. Siren is cake. Especially fun how squad tries to target her as she divebombs, so you can tell what direction she's going to come from.

But, a point or two on Zu. Killing eggs before they spawn (as far as I could tell) was an incredibly bad idea. Enrages boss, boss targets me, leads to death. Didn't know I could distinguish between the eggs; if cockerel eggs didn't trigger the enrage, might be a strategy. But the fact that you needed a potion and Second Wind both should be an indication that healer AI still needs improving.

Come to think of it, maybe the first time I cleared it, I did have an Arcanist. Really should've remembered that.