Ethersworn Adjudicator

The three-color tax is the whole bargain here. The body itself is mono-blue, but the removal ability demands one white and one black mana alongside its generic cost, which means the engine only comes online in a deck reaching across Esper colors. Pay that price and the payoff is relentless: a repeatable Mortify stapled to a flying 4/4, with the catch that tapping to destroy a creature or enchantment leaves the Adjudicator open on the crackback. That is what the untap clause answers. For two generic and a blue it stands the knight back up, converting a one-and-done removal effect into a control tower that can pick off a threat on each player's turn and still hold up as a blocker. The two abilities are designed to feed each other: the kill is gated behind colors the deck has to stretch for, and the untap is gated behind enough blue that you cannot fire it freely while also developing a board. Drawn out across a long game, it becomes an attrition engine that grinds enchantments and creatures into nothing while the flying body chips away. It belongs to an era of artifact-creature toolboxes that asked you to assemble a multicolor manabase before they paid out, rewarding the deck patient enough to keep mana open rather than the one looking for an immediate swing.