Unblockable Draw

Target creature gets +1/+0 until end of turn and can't be blocked this turn. Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Whenever you cast an instant or sorcery spell, you may put a charge counter on this creature. Whenever this creature deals combat damage to a player, you may draw X cards, where X is the number of charge counters on it.