Ace, Fearless Rebel

Ace, Fearless Rebel

Legendary Creature - Human Rebel | Power/Toughness: 2 / 2 (CMC 4)
Nitro-9 -- Whenever Ace, Fearless Rebel attacks, you may sacrifice an artifact. When you do, put a +1/+1 counter on Ace, Fearless Rebel, then it fights up to one target creature defending player controls.
Doctor's companion (You can have two commanders if the other is the Doctor.)