Shirei, Shizo's Caretaker is a uncommon Legendary Creature — Spirit card from Commander Masters (CMM), collector number 676. Current market price: $0.25 (foil $0.46), TCGplayer market prices via Scryfall.
Whenever a creature with power 1 or less is put into your graveyard from the battlefield, you may return that card to the battlefield at the beginning of the next end step if Shirei is still on the battlefield.