Mishra, Eminent One

Every combat, this turns a static artifact into a temporary body, and the design leans entirely on picking the right target. Copying a noncreature artifact you control (a mana rock, an equipment, a token-maker) and stamping it as a 4/4 Construct with haste hands you an attacker built out of whatever your board already offers, and if the copy carries an enters-the-battlefield trigger, you collect that value on the way in. The end-step sacrifice is the leash: nothing sticks, so the card asks for artifacts whose one-shot arrival is the payoff rather than artifacts you want to keep around. That framing pushes the deck toward ETB-heavy artifacts and sacrifice payoffs instead of a durable board, and it renders the historical Mishra flavor (the artifact-summoning brother) as a mechanic that literally clones your machines into war-forms each turn. Because the Warform is a full copy, it carries the source artifact's copiable values (including its activated abilities), so you can tap it, sacrifice it to an outlet, or feed it to anything that cares about tokens, copies, or artifacts entering before it dies at end step. What balances a repeatable free attacker is that it never accrues: you get the trigger and the swing, then start over next combat, so the ceiling is decided by how much value your artifact base can wring out of a single beginning-of-combat window rather than by piling up permanents.