I don’t think so. As I understand, the mode work like Delve, so that there is only one room with Doom troop in the end. (The key/scroll to this room is found by beating other normal rooms)
Having Doom-killer troop would be similar to having 3x-5x damage Construct Slayer in Hall of Guardian as 5th Faction troop, and that would be so imbalance.
But who know, maybe that would be a thing, but as spoiler data doesn’t point to any sides yet, I would still wishing it’s not the case.