Aegis of the Legion is a rare Artifact — Equipment card from Ravnica: Clue Edition (CLU), collector number 22. Current market price: $2.18, TCGplayer market prices via Scryfall.
Equipped creature gets +1/+1 and has mentor. (Whenever it attacks, put a +1/+1 counter on target attacking creature with lesser power.) Whenever equipped creature mentors a creature, put a shield counter on that creature. (If that creature would be dealt damage or destroyed, remove a shield counter from it instead.) Equip {3}