I don't know if anyone else has had this problem with the Hallway Room on Lvl 7 of Dungeon Doom, so I'm sharing my experience. After much frustration with this room, here is my solution:

1. Enter room wearing Crown
2. Kill 2 Dragons with Glass Swords
3. Kill 2 Demons
4. Remove Crown
5. Let Wisps teleport (probably 1 or 2 appear at first)
6. Put Crown back on, stops Control from Wisps
7. Kill Wisps
8. Repeat steps 4-7 until you have killed all 6 Wisps
9. KILL SANDTRAPS, the one in the center of the room hides a ladder down
10. If you want to leave and camp after the battle, make sure you have seen the VICTORY message, otherwise the room occupants regenerate when you re-enter.