Avatar Roku, Firebender {3}{R}{R}{R}
Legendary Creature — Human Avatar
RedCommander: legal
Identity
Red
EDHREC rank
#4,772
Cheapest printing
US$11.73
TCGplayer
Printings
2
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.
Every printing
highest TCGplayer market first; a card with only a thin single listing shows its low
In short
A Commander deck is a commander and 99 other cards, one copy of each (except basic lands), all inside the commander's colour identity. Paste a full list into the deck price calculator to price it and check it against the format.