This ingenious loop relies on Isilu, Carrier of Twilight—the transformed back face of Eirdu, Carrier of Dawn—to grant persist to Elegant Edgecrafters, ensuring that every time the Edgecrafters heads to the graveyard, it comes right back with a -1/-1 counter. Phyrexian Altar provides the sacrifice outlet to start this cycle while generating a steady stream of colored mana with every trip. Meanwhile, Elegant Edgecrafters's own fabricate 2 ability triggers upon its return, allowing you to place a +1/+1 counter on it that immediately neutralizes the persist-induced -1/-1 counter via state-based actions. Because these opposing counters wipe each other out, the Edgecrafters is left with a clean slate to be sacrificed all over again, fueling infinite sacrifices, death triggers, and mana of any color.