Atraxa, Praetors' Voice

Four colors, four keywords, and a proliferate trigger that recontextualized an entire mechanic. Proliferate had existed as a clever-but-narrow tool, mostly remembered as the engine behind a few infect and superfriends builds; what this design did was attach it to a four-mana evasive body that protects itself and wins races on its own. The result is that the proliferate is gravy, not the gameplan. You are fielding a 4/4 flier with vigilance, deathtouch, and lifelink that, on each of your own end steps, grows every loyalty count, every charge counter, every +1/+1 spread across your board. That decoupling (a fair, complete creature with an open-ended counter payload bolted on) is why the card became the default home for counters-matter decks rather than a build-around that demands them. The four-color identity matters too: it asks for almost nothing in return for permission to play every counter synergy in the game at once. Planeswalkers tick toward ultimates a turn early, +1/+1 strategies snowball, and doubling effects chain off the same trigger. And the end-step cadence is the discipline the design leans on: proliferate fires once, as your turn winds down and control is about to pass to the next player, so the payload compounds at your pace rather than ratcheting up every time counters change hands. The body would close games on its own; the proliferate is what made it a format institution and the face of an archetype that had no clean leader before it arrived.