This ingenious loop relies on turning a defensive cleric into a self-sustaining engine, powered by the synergy between Barrenton Medic and Flourishing Defenses. By placing a -1/-1 counter on Barrenton Medic to untap it, you trigger Flourishing Defenses to spawn a green Elf Warrior. That new arrival promptly sets off the Alliance ability of Mighty Mutanimals, dropping a +1/+1 counter onto the Medic that immediately cancels out the -1/-1 counter keeping the whole loop balanced. Through this elegant dance, Mighty Mutanimals's entry trigger feeds the chain while keeping your key creature alive indefinitely, yielding an endless horde of creature tokens.