Mockingbird, Ace Agent

Double strike on a 2/2 body reads like a Voltron finisher, but the growth condition rewards something less obvious than piling buffs onto one creature. The counter lands whenever you cast any spell targeting a creature you control: a protective pump, a combat trick, an aura, even a bounce or blink cast for value on your own board. Because double strike converts each counter into two points of combat damage, the incentive isn't to overload a single explosive turn but to chain cheap targeted spells across many turns and let the body compound quietly. That modest base is the tension the design lives on: without a deck stocked with things to aim at your own creatures, it grows too slowly to matter and the double strike doubles nothing. The clever part is that the counter accrues regardless of why the spell was cast, so a deck already leaning on instant-speed protection and tricks collects the growth as a rider on spells it was going to fire anyway. That is the axis this rewards: not one big turn, but the slow accumulation of every defensive spell you cast to keep the board alive, banking permanent power onto a creature that connects twice.