Mikaeus, the Lunarch is a mythic Legendary Creature — Human Cleric card from Foundations Jumpstart (J25), collector number 225. Current market price: $0.58, 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.