Evolution Witness

Adapt's whole premise is that it fires exactly once: the "if this creature has no +1/+1 counters" clause is a self-canceling gate, so once you pay to grow the creature, the button goes dead because the counters are already there. This card takes that one-shot growth and welds a recursion engine to it, then quietly rewrites the terms. The return trigger keys off "whenever one or more +1/+1 counters are put on this creature," from any source, not off the adapt keyword itself. So the built-in adapt is really a two-mana permanent-card retriever with a body attached, and any other way to place a counter re-arms a recursion the keyword's own text can never repeat: a proliferate effect stacking onto the counters already present, a separate counter-granting spell, any effect that literally puts a counter rather than applying a static buff. That is the tension worth sitting with. The ability adapt shuts off after one use is exactly the ability the card wants to fire again and again, and it leaves you to route around the keyword's dead-button clause by hand. The return is not restricted to creatures, so the same trigger rebuilds a fallen mana rock, a land, an enchantment engine, whatever permanent card is sitting in the yard. The 2/1 body for is fragile by design; the payoff scales entirely with how many times you can convince a fresh counter to land on it.