The Deal of Destiny

Each time a card(s) you control is destroyed by battle or card effect, place 1 Emperor's Key Counter on this card (max. 1). If your opponent Special Summons a monster(s) from the Extra Deck (except during the Damage Step): You can remove 1 Emperor's Key Counter from this card; send 1 "The Door of Destiny" from your hand, Deck, or face-up field to the GY, Special Summon 1 LIGHT "Utopia" or "Utopic" Xyz Monster from your Extra Deck, and if you do, attach this card to it as material. (This is treated as an Xyz Summon.) You can only use this effect of "The Deal of Destiny" once per turn.