Umbra Mystic is a rare Creature — Human Wizard card from Wilds of Eldraine Commander (WOC), collector number 82. Current market price: $5.76, TCGplayer market prices via Scryfall.
Auras attached to permanents you control have umbra armor. (If an enchanted permanent you control would be destroyed, instead remove all damage from it and destroy an Aura attached to it.)