Livaan, Cultist of Tiamat {2}{R}
Legendary Creature — Dragon Shaman
RedCommander: legal
Identity
Red
EDHREC rank
#9,367
Cheapest printing
US$0.20
TCGplayer
Printings
3
Whenever you cast a noncreature spell, target creature gets +X/+0 until end of turn, where X is that spell's mana value.
Choose a Background (You can have a Background as a second commander.)
Keywords: choose a background
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.