Shapesharer

Because Changeling makes this a creature of every type, it is always a legal target for its own ability, which is the whole trick: hold up two mana and your blue, and at instant speed it can become a copy of the biggest body across the table, renting that shape only until your next turn before reverting to a 1/1. That temporary clause is the lever the design pulls. You are leasing a form for a turn cycle and paying again to renew it, so the activation reads less like a one-time Clone and more like a response held up across both players' turns. The deeper use is that the ability targets any Shapeshifter, not just this one, so a board with other changelings or copy effects becomes a pool of bodies you can reshape on demand. Worth being precise about the limit, though: becoming a copy of a creature already on the battlefield does not retrigger its enters-the-battlefield abilities, since nothing is entering. The value loop here is about combat math and copying static or attack-relevant bodies, not about milking ETB triggers off a reset each turn. What it really wants to be is a toolbox: an answer card wearing the costume of a tribal payoff, flexible enough to be a blocker, a temporary finisher, or a way to break a stalemate by mirroring whatever is winning it.