Firebending Student (TLA 342)

Creature — Human Monk • Mana cost: {1}{R} • Avatar: The Last Airbender • Rare

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Firebending X, where X is this creature's power. (Whenever this creature attacks, add X {R}. This mana lasts until end of combat.)

Illustrated by Ina Wong.