Dyadrine, Synthesis Amalgam
The X-cost body is a familiar shape: pour mana in, get a proportionally large creature. What separates this construct from the usual scaling threat is that it treats its +1/+1 counters as a fuel supply rather than a stat line. The attack trigger converts stored counters into cards and bodies, pulling one counter each off two creatures you control to draw and build a 2/2 Robot. That turns the counters you paid for into a repeatable engine, but the cost of admission is a second body: the ability names two creatures, so this legend cannot feed on itself. Alone on the board, the engine simply does not turn. It wants a wide counters-matters battlefield that can absorb the recurring drain, and the Robot tokens it generates are part of the answer, replenishing the board it depletes and eventually becoming counter-bearers of their own if you have the anthems to prop them up. Trample on a variable-sized body means the counters do double duty, threatening damage while they sit and converting to advantage when spent. The design tension is in that dependency loop: it is a counter-sink and a value engine housed in one two-color legend, but only if the rest of the board keeps pace with its appetite.
