Nantuko Mentor

Doubling a creature's power instead of adding a flat bonus makes this a multiplier rather than an additive pump, and that distinction is the entire design. Point it at a 4/2 attacker and the swing reads +4/+4: an 8/6 that turn. The effect scales with the power already on the board, so each activation pays off more on a creature that is already large rather than one that needs incremental help, and because the bonus is symmetric, it pads toughness too, letting an overcommitted attacker survive a block it would otherwise lose. The activation cost is heavy for a repeatable effect, and the tap is the brake: one target per turn cycle, which keeps the multiplier from chaining inside a single combat. On a 1/1 body, the Mentor is pure setup, and that is also its weakness. The card does nothing the turn it lands and demands a sizable creature already in play to point at, so the controller is the one paying the tempo: three mana for a defenseless body that then has to survive a turn and untap before it doubles anything. Conceptually it is a Berserk-adjacent doubler you can fire every turn, turning one trampler into a one-shot kill. The rate is what dates it: an early-era repeatable engine priced like a midrange threat but stapled to a body that answers nothing on its own, in a period when cheap removal cleared the 1/1 before it ever paid off. Sound as a concept, the math around it never lifted the card past a niche tool in fatty-green builds.