Avatar Roku, Firebender (TLE 191)

Legendary Creature — Human Avatar • Mana cost: {3}{R}{R}{R} • Avatar: The Last Airbender Eternal • Mythic

Whenever a player attacks, add six {R}. Until end of combat, you don't lose this mana as steps end.
{R}{R}{R}: Target creature gets +3/+0 until end of turn.

"Make sense of our past, Aang, and you will bring peace, and restore balance to the world."

Illustrated by Toni Infante.