Zolin Blood Priest is impossible

I don't know if this is a bug or if this is intended (and if it is intended, it's incredibly stupid). I've failed this fight twice, not because I died, but because the game effectively softlocked me.

I think the way this fight is supposed to go is that Zolin drains the girl to death, then he becomes vulnerable and can be beaten. What actually happens, twice now, is that the girl goes into a downed state while the guy keeps going...

But for some reason he can still drain life from her.

So unless you do 50 bajillion DPS and can beat his healing (which my incredibly tanky but single-target deficient essence drain witch can't really do), you're stuck. You just don't have the numbers to beat him.

Please fix this fight, I'd like to be done with the campaign one day.

I beat the fight, first try no deaths, with an ice strike invoker. My DPS was probably about 6,000 at the time. Have you tried slotting Acrimony on a chaos or poison skill?

Well, that worked.

But it's still bullshit that the fight even ends up in this situation. Why can he drain her when she's down? Feels like a bug.