Demon of Wailing Agonies is a rare Creature — Demon card from Commander 2014 (C14), collector number 21. Current market price: $1.70, TCGplayer market prices via Scryfall.
Flying Lieutenant — As long as you control your commander, this creature gets +2/+2 and has "Whenever this creature deals combat damage to a player, that player sacrifices a creature of their choice."