This clever loop turns the graveyard into a mechanical workshop by exploiting Haakon, Stromgald Scourge's static ability, which generously allows you to cast Knight spells directly from your graveyard. While that usually restricts you to traditional tribal choices, Universal Automaton brings the vital Changeling keyword to the table, registering as a Knight so it can repeatedly benefit from Haakon's recursion. Finally, Basal Sliver completes the engine by giving every Sliver—including our shape-shifting automaton—the ability to sacrifice itself for a quick burst of black mana. By repeatedly cashing in the Universal Automaton for mana and using that exact mana to recast it from the graveyard, you generate infinite black mana along with an endless stream of sacrifice, death, and entry triggers.