I just got Forgotten Souls a couple of days ago and had a chance to try it out on my own this morning. I picked Avric and Ashrian (both of the Healers from the 2nd Edition core box).
I thought Defenders of the Realm was unforgiving....
I'm pretty sure I'm misinterpreting the rules (it wouldn't be the first time with a Fantasy Flight game). Here's what kept happening pretty much every room: the timer for the room would run out, Doom would advance by 1, and the Encounter card would be discarded. Since the Encounter card is no longer in play, Fate would also advance by 1 and I would have to draw a Peril card.
On the one or two rooms where I managed to complete the objective before the timer ran out, it was with my second to last action which left me with either ending my turn and drawing a Peril card since the Encounter card was no longer in play or opening the door and moving on to the next room.
Choosing to move to the next room resulted in what amounted to the Overlord phase happening twice in row. Opening the door would result in the next Encounter card being turned over and the room set up. Each time, the monsters got a "free" turn with a "After setup, activate monsters (usually Flesh Molders). Since I was using my last action with my second hero to open the door, my turn ended at that point. This caused the Encounter card text to activate, the timer to advance by 1, and the monsters to act again and all I've done at this point is open the door.
Normally, I might be able to handle this but I usually didn't make it out of any room with more than half health and a point or two of fatigue (no time to Rest since all my actions went into meeting the objective and moving to the next room before I had to draw a Peril card).
If I'm doing something wrong, please let me know for my next attempt.
If everything there was correct, I'm going to let Forgotten Souls Overlord for me next time because it was doing a way better job than I ever have (which is embarrassing to admit).
Thanks for reading this and for any help you can give.