It seems this quest is bugged right now. The final dialogue just doesn't go through. You have two choices, no matter which you select, it just ends the dialogue (and you can click through again) but no quest state is triggered.

Had the same problem. Had to reload a autosave 2 hours before. Thank god it worked because killing the demon without snuffing out the candles didn t finish the quest for me.

Malady just refuses to talk to you even if you killed the demon and saved everyone without blowing out the candles - "you'll 100% die in that mansion" she says, "good luck" and so on. That was my first walkthrough. My second walkthrough ended up with Malady refusing either to cast rain on the candles or hearing my rejection, she just ends the dialog and nothing happens. This game is just swarming with all kind of nasty bugs at the moment and this quest especially.

For me Malady was never there, since she died just after the Act3 cutscene, exhausted from controlling the ship. So i don't know what triggers that, and that doesn't happen for most people. Could be a bug, related to a previous quest, since the game has many. And it prevents you from going back to the hall of echoes too, so it's a bit of a pain.
One explanation could be that you're limited to 3 supporters that will revere you before the last fight, and that give you a -3 SP bonus. In that case, you couldn't have both Almira (the succubus) and Malady, and the latter dies. But that's really just a wild guess

Is anyone having problems with Malady not using the flood that wipes the candles at the end? I keep telling her to do it but she just doesn't flood it and when I leave the plane, it ends the quest without weakening him.

Is this a quest only possible to activate if you have Lohse as one of three companions that survived at the end of Act 1? Can't seem to get this quest no matter what.

BE WARNED

Not snuffing the candles while playing as lhose will give you insta game over when you confront the demon as he will possess you in the 3rd turn and there is nothing you can do about it

Doesn't need to be weakened at all, you simply have to kill him before he transforms using arrow storm or a similarly extremely high damage attack. you need more than 40 initiative, and that character needs to have the highest initiative of any of your party to go first.

Holy moly, hardest opponent so far since Radeka of Act1. Adramalik is one tough opponent. It's true, the nurses keeps buffing him. A real fight that I won, using a glitch. First, I was thinking, maybe I need Jahan or Malady or Almira to help me out, like lets gangbung adramalik. But no, I can't find them. So here is what I did to beat him. Follow the tip, you have to kill them nurses first. So the first nurse at the reception, kill that in cold blood. Yeah, talk to the nurse and load up your characters to kill it. Once killed, all the other nurses will come to your area and fight. Even adramalik will come to fight, he will transform to demon form asap. Kill one or two more nurses, after that your are already near dead from the damages. Maybe one or two of your characters are already dead. I got two ashes of idol rebirth or something so I have insta-alive but whatever. At this point, I have killed 3 nurses already. Dont mind admalik, he is so strong your damage wont even matter. Just attack the nurses. At this point, only my main character is alive, and all my other 3 guys are dead. Run to the exit. Yeah! Use jump, tactical retreat, phonex whatever, just to back to the front door. Once you are outside. Heal, and then here is the tricky part, go back again to the house, this time, via sneak mode. dont worry, admalik, still in his demon form will be in the room and he walks back and forth but not much out of the area. thats why your characters must not get close to adramalik's room when fighting. so that he wont see you resurrect them and then you go insta battle again. what you do is resurrect all your characters one by one and sneak/run/gtfo of the house. once outside the house. Heal all. Now, with 4 healthy characters go back and fight him again. In my fight, there was still one nurse left, so its 4 vs 2. Nonetheless with new fresh and healthy party. I finally beat adramalik and the nurse. (I killed adra first, then the nurse-which is kinda ironic, i want adra to die last but whatever)...... then lohse will give you a surprise which kinda made my day.