All-Seeing Arbiter

Two triggers stitched together into a combat engine: every entry and every attack loots (draw two, pitch one), and the discard half of that loot fires the second ability, shrinking a blocker's power by however many distinct mana values sit in your graveyard. That second trigger is the sly part. Nothing on the card cares about card count or creature type in the yard; it counts variety of mana values, so a graveyard stocked with a one-drop, a three-mana spell, and a five-drop is worth more than three copies of the same card. The design rewards a diverse curve of discards rather than raw volume, which is an unusual axis to build around. The -X/-0 never kills, only defangs, but that cuts both ways: a 5/4 flier that reloads its own hand each swing while neutering the biggest ground threat, whether it comes down to attack or to stabilize by shrinking an incoming attacker. Because the debuff persists until your next turn, the window is your opponent's entire turn cycle, not just the current combat step, which quietly matters for anyone hoping to race back through a shrunken wall. It is a top-end evasive engine that folds card advantage and blocker suppression into a single body, asking only that your graveyard grow more varied as the game goes long.