Akki Battle Squad

Extra combat steps have always come with a tax to keep them honest: the classic ones untap nothing, forcing you to attack with what survived the first swing, or they hand the extra phase to a creature that already tapped to attack. This one pays that tax with the deck it demands you build. The trigger keys off modified creatures, so the untap-and-extra-combat only pulls its weight if your board is carrying Equipment, Auras, and counters, and the payoff scales exactly with how many of those bodies you've dressed up: every modified attacker refreshes and swings again. That's a design that couples the extra combat to a Voltron or aura-heavy engine rather than to raw creature count, which is why the reward is untapping all your modified creatures rather than a single chosen attacker. The once-per-turn clamp is the load-bearing restriction; without it a second modified attack would loop into a third, a fourth, and the whole thing collapses into an infinite-combat enabler. As written, it grants precisely one bonus phase, big and predictable. The 6/6 body matters here too: it wants to be modified itself, becoming both the engine and one of the attackers the engine untaps, which means a single piece of equipment turns it into a repeatable threat rather than a one-shot Overrun.