Prosper, Tome-Bound (Forgotten Realms Commander)

Legendary Creature Ñ Tiefling Warlock - Deathtouch
Mystic Arcanum Ñ At the beginning of your end step, exile the top card of your library. Until the end of your next turn, you may play that card.
Pact Boon Ñ Whenever you play a card from exile, create a Treasure token.