When the final battle starts the overlord:
1. The overlord removes all monsters other than the Avatar from the board, discards all of his Overlord cards, and puts the Overlord deck away.
2. Each hero’s maximum wounds are increased by +1 for every 2 conquest tokens the heroes collected since entering the Overlord’s Keep.
3. The Avatar’s maximum wounds are increased by +2 for every conquest token the overlord scored since the heroes entered the Overlord’s Keep.
#1 can be read two ways. The first would discard all overlord cards in his hand, in play, or in some sort of limbo (as with In My Parlor). The second would let the cards from In My Parlor stay around.
Anyone know which it is? I'm pretty sure that the In My Parlor cards go away too, but if they don't that would be a big boost to the Spider Queen, who definitely seems like the weakest of the avatars once the final battle starts.