Chronomaly Crystal Skull (REDU-EN013) - Return of the Duelist Unlimited

If you control a face-up "Chronomaly" monster: You can discard this card to the Graveyard; add 1 "Chronomaly" monster from your Deck or Graveyard to your hand, except "Chronomaly Crystal Skull". The effect of "Chronomaly Crystal Skull" can only be used once per turn.