Darwin, Adaptive Mutant

Evolve on most creatures is a passive accumulator: bigger things enter, counters pile up, and the growing body is the whole reward. Here the counters double as ammunition. Removing two of them converts stockpiled size into indestructibility for the turn, so every larger creature you deploy is not just growth but a stored answer to a board wipe or a bad block. The loop is unusually forgiving, too: spending counters makes him smaller, which lowers the bar for the next entering creature to clear his power or toughness, so cashing in protection actually makes evolve easier to trigger again. That means the engine self-corrects rather than stalling out. The name earns itself; a creature that literally reshapes to survive whatever threatens it. But the design does more than gesture at flavor: it takes a keyword built for green's go-wide midrange, historically a slow-payoff mechanic that only pays in raw stats, and hands it a self-protection valve. A two-drop that would ordinarily be an early trade instead banks turns of durability with each larger body that follows it. Indestructibility here is the interest on having played out a curve of ever-bigger creatures, not a stapled-on evasion clause, and because activation refills its own fuel line, the more aggressively you use it the more the counters keep coming back.