Mikaeus, the Lunarch is a mythic Legendary Creature — Human Cleric card from Jumpstart (JMP), collector number 123. Current market price: $0.86, TCGplayer market prices via Scryfall.
Mikaeus enters with X +1/+1 counters on it. {T}: Put a +1/+1 counter on Mikaeus. {T}, Remove a +1/+1 counter from Mikaeus: Put a +1/+1 counter on each other creature you control.