The Akroan War is a rare Enchantment — Saga card from Theros Beyond Death Promos (PTHB), collector number 124p. Current market price: $0.25 (foil $0.68), TCGplayer market prices via Scryfall.
(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.) I — Gain control of target creature for as long as this Saga remains on the battlefield. II — Until your next turn, creatures your opponents control attack each combat if able. III — Each tapped creature deals damage to itself equal to its power.