Warden of the Grove
Left unmolested, this 2/2 simply grows on its own end step, one counter at a time, into a slow but inevitable clock. The compounding part is what it does to everything that follows it: each subsequent nontoken creature you control arrives endured for however many counters have stacked up, and you choose whether to load those counters onto the newcomer or peel off a white Spirit of equal size. That second mode diffuses the card's obvious weakness, since the accumulated payoff sits in banked tokens and enlarged bodies rather than in the fragile creature that generated them. The whole design is a wager on time. It wants to survive turns to inflate the multiplier, and the opponent's problem is that answering it late means answering a board that has already flooded out. Endure is the mechanism that lets one keyword serve two masters, feeding a counters-matter shell or a token-swarm one from the same trigger, and it means the buff never stays static the way a conventional anthem does: it ratchets, so the creature you cast on turn eight collects a bonus that dwarfs the one on turn four. A lord hands every creature the same fixed bump; this hands out a number that keeps climbing, which is a very different threat to have to race.
