Shield of the Avatar is a rare Artifact — Equipment card from Magic 2015 (M15), collector number 230. Current market price: $0.38 (foil $0.96), TCGplayer market prices via Scryfall.
If a source would deal damage to equipped creature, prevent X of that damage, where X is the number of creatures you control. Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)