Cavalier of Dawn is a mythic Creature — Elemental Knight card from Core Set 2020 Promos (PM20), collector number 10p. Current market price: $14.91 (foil $11.95), TCGplayer market prices via Scryfall.
Vigilance When this creature enters, destroy up to one target nonland permanent. Its controller creates a 3/3 colorless Golem artifact creature token. When this creature dies, return target artifact or enchantment card from your graveyard to your hand.