Marina Vendrell's Grimoire (64) [Duskmourn: House of Horror]

When Marina Vendrell's Grimoire enters, if you cast it, draw five cards. You have no maximum hand size and don't lose the game for having 0 or less life. Whenever you gain life, draw that many cards. Whenever you lose life, discard that many cards. Then if you have no cards in hand, you lose the game.