There was a time when an adage ruled the Sith Order; that there could only be Two. Legitimacy is a fine thing to have, though one would say that it is something that, for a Sith, must be enforced, or it's value degrades where there are more fools calling themselves Sith than just two. Equally, however, comparing a Dark Lord of the Sith to a Prophet, to a cultist, or to a simple Dark Jedi, is an exercise in mortality. The two dovetail; a Dark Lord who surrounds himself with an excessive number of minions will eventually fall to them, no matter his prowess. Yet, a Dark Lord without a Shadow Hand is less than nothing; to have someone that powerful at ones beck and call is power distilled, to own someone so fully that they will sacrifice themselves in order to further their own progression through power, which, of course, is only through you as their Master. Even through the history of massive Sith Orders, the reigning Dark Lord would have his own Shadow Hand, and then, when the Order shrank, that self-same system would persist; a Rule of Two within the Rule of the Strong; Sadow and Nadd; Nadd and Exar Kun; Exar Kun and Ulic-Qel Droma; Darth Revan and Darth Malak. Only the greatest failures of the Sith dispensed with this simplest facet, only the most successful distilled it down to just two, in the most literal sense, as did Sadow when he was bereft of an Empire.
So why was it that nobody looked at Darth Gorog and did not ask of themselves; if Darth Gorog was a member of the greatest Sith Order in history, then which was he? The Master, or the Apprentice?
Allow me to answer for you.
He was the apprentice.
Twenty six millennia ago the Celestials domain fell, at my hand. And while the surviving Celestials were content to separate the Killiks and Darth Gorog, one to the Unknown Regions and one to Sarafur, all but half a galaxy away from each other, that they could not with the master, with the architect of their fall. So not only did they force me into stasis, and trap my hive around me, the Soros, so named for myself, they kept their most loyal hive, Ouroboro, on Alderaan, beneath the surface, a layer between the humans that would inevitably colonise it, and my so-called Black Hive below.
With my body in stasis my mind has been free to direct my vassals to the surface to absorb Joiners periodically, to keep apprised of galactic events. The Order of Extermination has kept the existence of the Killiks mere legend, which, too, serves my purposes. With the re-emergence of the Sith, not as proxies behind Dark Jedi, or as short lived uprisings that I could take little advantage of, I was able to push into motion my own plan, allowing for the Empire's struggle to conceal my emergence after more than twenty six millennia. Sabotaging the Imperial offensive with my Killiks, then sabotaging the aftermath and riling up the ordinarily peaceful human inhabitants to civil war, I am ready to emerge in the middle of the renewed conflict between the Empire and Jedi, and seize back control of the Order. It is just a matter of time, something that I, safe within my stasis vault, have a vast amount of. I have waited out Darth Malgus and his New Empire, the Dreadmasters and their Hutt puppets, Darth Revan and his failed efforts to destroy Vitiate; now I just need wait out Valkorian and his Eternal Empire.
No Emperor will stop me.
No Dawn Herald.