Dark Side Undead, a Sith Lich unleashed from the Valley of the Dark Lords on the Sith tomb world Korriban. He unleashes a biomechanical plague upon the galaxy that infects both flesh and machine, from Ewoks to Starships. The infected are used to create a horrifying biomechanical fleet that consumes entire worlds like locusts, collecting biomass and resources to build a massive megastructure called the Annulus.
The Annulus is a biomechanical megastructure both alive and dead that can open a gate through an ancient hyperspace barrier into the unknown regions, where an unimaginable horror of galactic proportions awaits.