Serkuleks

Serkuleks, the Fount is a Fallen Servitor of the House of Dusk. It is the final boss of the Enhance! world quest, where it works with Raksil, Archon Priest to distribute an enhanced form of Ether in the European Dead Zone.

Overview

During the Red War, the House of Dusk used stolen Cabal technology and Serkuleks to make a more potent variant of Ether. Fallen who consumed it became Empyrean Fallen, gaining greater strength and health. The project ended when a Guardian destroyed Serkuleks. The source does not say how the two created the substance.