Moonveil Regent is a mythic Creature — Dragon card from Innistrad: Midnight Hunt Promos (PMID), collector number 149p. Current market price: $0.56 (foil $0.86), TCGplayer market prices via Scryfall.
Flying Whenever you cast a spell, you may discard your hand. If you do, draw a card for each of that spell's colors. When this creature dies, it deals X damage to any target, where X is the number of colors among permanents you control.