Crown of Ascension is a common Enchantment — Aura card from Onslaught (ONS), collector number 78. Current market price: $0.06 (foil $0.77), TCGplayer market prices via Scryfall.
Enchant creature Enchanted creature has flying. Sacrifice this Aura: Enchanted creature and other creatures that share a creature type with it gain flying until end of turn.