Inner Demon is a uncommon Enchantment — Aura card from Battlebond (BBD), collector number 48. Current market price: $0.23 (foil $1.98), TCGplayer market prices via Scryfall.
Enchant creature Enchanted creature gets +2/+2, has flying, and is a Demon in addition to its other types. When this Aura enters, all non-Demon creatures get -2/-2 until end of turn.