Door of Destinies is a rare Artifact card from Secret Lair Drop (SLD), collector number 1631★. Current market price: — (foil $19.37), TCGplayer market prices via Scryfall.
As this artifact enters, choose a creature type. Whenever you cast a spell of the chosen type, put a charge counter on this artifact. Creatures you control of the chosen type get +1/+1 for each charge counter on this artifact.