Dathka Graush

Dathka Graush was a Sith sorcerer who lived on the planet Korriban more than seven thousand years before the Battle of Yavin. Brutality and trepidation were the tools Graush used to defeat his enemies during one of Korriban's recurrent civil wars, the end of which saw him acclaimed king of his species. In the war's wake, Graush made use of both Sith sorcery and alchemy to perfect the Tsaiwinokka Hoyakut spell, through which he resurrected an army of reanimated corpses bound to him through the dark side of the Force. He also had his heart removed and replaced with a magical crystal that was imbued with the power of the Force's malevolent side. The Graush dynasty ultimately culminated with his death at the hands of assassins, and the Sith King was interred within Korriban's Valley of Golg.

Sometime between the destruction of the first Death Star and the Battle of Endor, the spirit of the long-dead Sith King was disturbed after millennia of slumber. Cronal, a dark side prophet formerly in the service of his Imperial Majesty Palpatine, forcefully sundered Graush's ghost from his Korriban grave and compelled the Sith King to reveal the most potent of his alchemical secrets. The knowledge Graush imparted to Cronal assisted the latter in the creation and manipulation of the electromagnetically-charged meltmassif crystals.

Text and facts from the “Dathka Graush/Legends” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.