CardName: Flamewall Bender
Cost: 1R
Type: Creature - Human Soldier
Pow/Tgh: 1/1
Rules Text: {X}{R}{R}: Flamewall Bender gets +X/+4 until end of turn.
Use this ability only if Flamewall Bender is blocking.
Flavour Text:
Set/Rarity: Avatar: The Last Airbender None
Flamewall Bender
Creature – Human Soldier
: Flamewall Bender gets +X/+4 until end of turn. Use this ability only if Flamewall Bender is blocking.
I don't know why red gets walls, but apparently it does. Here's a variant maybe appropriate to firebending, though a little more complicated.