The Aetherspark (231) [Prerelease Cards]

As long as The Aetherspark is attached to a creature, The Aetherspark can't be attacked and has "Whenever equipped creature deals combat damage during your turn, put that many loyalty counters on The Aetherspark." +1: Attach The Aetherspark to up to one target creature you control. Put a +1/+1 counter on that creature. −5: Draw two cards. −10: Add ten mana of any one color.