The Mindskinner is a rare Legendary Enchantment Creature — Nightmare card from Duskmourn: House of Horror Promos (PDSK), collector number 66s. Current market price: — (foil $6.46), TCGplayer market prices via Scryfall.
The Mindskinner can't be blocked. If a source you control would deal damage to an opponent, prevent that damage and each opponent mills that many cards.