Special Summon 1 "Mimighoul" monster from your hand or Deck to your field, or in face-down Defense Position to your opponent's field, then you can change 1 face-up monster on the field to face-down Defense Position. You can banish this card from your GY, then target any number of "Mimighoul" cards you control; return them to the hand. You can only use 1 "Mimighoul Room" effect per turn, and only once that turn.