Overwhelming Splendor is a mythic Enchantment — Aura Curse card from Hour of Devastation (HOU), collector number 19. Current market price: $6.93 (foil $16.91), TCGplayer market prices via Scryfall.
Enchant player Creatures enchanted player controls lose all abilities and have base power and toughness 1/1. Enchanted player can't activate abilities that aren't mana abilities or loyalty abilities.