Beastmaster Ascension is a mythic Enchantment card from Avatar: The Last Airbender Eternal (TLE), collector number 39. Current market price: $4.78 (foil $8.46), TCGplayer market prices via Scryfall.
Whenever a creature you control attacks, you may put a quest counter on this enchantment. As long as this enchantment has seven or more quest counters on it, creatures you control get +5/+5.