The Balrog, Flame of Udûn {3}{B}{R}
Legendary Creature — Avatar Demon
Identity
Rakdos
EDHREC rank
#21,461
Cheapest printing
US$0.25
TCGplayer
Printings
3
Trample
When a legendary creature an opponent controls dies, put The Balrog on the bottom of its owner's library.
Keywords: trample
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.