This clever loop turns a simple goblin sacrifice into an endless cycle of doom, fueled by the clever synergy between Metallic Mimic and Putrid Goblin. Because Metallic Mimic grants an entering Goblin an extra +1/+1 counter, it instantly cancels out the -1/-1 counter that Putrid Goblin's persist ability would normally apply, allowing the goblin to return to the battlefield fresh and ready to die again. Sling-Gang Lieutenant acts as both the executioner and the win condition, taking full advantage of the endless sacrifices to drain your opponents of their life while keeping you comfortably padded with infinite lifegain.