The Aetherspark (DFT #231)

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.