This explosive infinite loop is fueled by Krenko, Mob Boss, whose tap ability rapidly multiplies your board state by generating a swarm of Goblin tokens equal to the number of Goblins you control. While Aggravated Assault provides the crucial extra combat phases and untaps to keep the momentum going, it demands a heavy mana investment to continually activate its ability. That's where Phyrexian Altar steps in as the engine's heart, converting that newly birthed horde of token sacrifices directly into the precise colored mana needed to pay for the Assault—leaving plenty of leftover Goblins to exponentially grow the army with each iteration.