Flickering Ward is a uncommon Enchantment — Aura card from Mystery Booster 2 (MB2), collector number 11. Current market price: $0.50, TCGplayer market prices via Scryfall.
Enchant creature As this Aura enters, choose a color. Enchanted creature has protection from the chosen color. This effect doesn't remove this Aura. {W}: Return this Aura to its owner's hand.