Vitiate's "domination" on Nathema
It's time to put the fanfics about Vitiate dominating eight thousand Sith to rest.
First, the feat itself:
Once they arrived on Nathema, they quickly fell under Lord Vitiate's control. He dominated their minds, crushed their resistance. He turned them into slaves to his will, forcing them to participate in the most complex ritual of Sith sorcery ever attempted. Calling on the dark side, Lord Vitiate devoured them. He fed on their power, absorbing it into himself, utterly obliterating all traces of his victims.
-Darth Nyriss, The Old Republic: Revan
It would be impressive if not for the fact that they were told by Darth Nyriss, a Sith Lord who lived over a thousand years after the event. She couldn't possibly know if the historical records are correct, or she may have fabrcated the tale entirely. In short, her word isn't reliable.
Second, there are multiple versions of this story:
An ancient Dark Lord of the Sith named Darth Vitiate destroyed all life on Nathema with a ritual designed to grant him immortality.
-Force and Destiny
Eight thousand Sith Lords gathered on Medriaas and agreed to partake in a ritual that would bind the Sith together as an ultimate dark side weapon.
The ritual lasted ten days. Lord Vitiate orchestrated the sorcery and the planet Mediraas was consumed by the largest dark side nexus the galaxy would ever see. When the ritual ended, Lord Vitiate emerged as the only survivor. The pain, energy, and suffering of every living entity on the planet fueled his power and would prolong his life for centuries.
-The Old Republic Encyclopedia
What is known is that following the flight of Naga Sadow, the Emperor came to Korriban, gathered the remaining lords of the Sith and took them back with him to Nathema. There they conducted a ritual that extended the Emperor's life at the cost of the lives of more than eight thousand Sith Lords. The Ritual of Nathema is celebrated among Imperial scholars as a rare and amazing coming together of Sith for the good of the Empire.
-The Old Republic Codex: The Ritual of Nathema
In Force and Destiny, no mention of any domination is made. In TORE and the Codex, the notion of Vitiate dominating the Sith is outright contradicted by them agreeing to it willingly. The word of Darth Nyriss isn't any more valid than any other Imperial scholar's. All three of these works also came after Revan, and all of them agree on the fact that no domination ever happened, so we can safely treat is as a retcon.
And lastly, all word-of-mouth feats have officially been declared non-canon within the Legends timeline. This is the nail in the coffin: