Mai, Jaded Edge (#147)

Type: Legendary Creature — Human Noble

Text: Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Exhaust — {3}: Put a double strike counter on Mai. (Activate each exhaust ability only once.)

"Finally, something to do."

Set: Avatar: The Last Airbender (#147)