Force predator called the Nameless (sometimes also called Levelers). These monstrous creatures hunt the Force, and they feast on Force-sensitives, drawing the midi-chlorians out of them and reducing them to lifeless, calcified husks. They are incredibly sensitive to the slightest fluctuation of the Force, and in Justina Ireland's novel Path of Deceit one Nameless can sense the presence of a Force relic, and stalks around it hungrily.
Only one Force group could possibly survive the Nameless; the Sith, who had learned to conceal their own Force presence. As seen in the prequel trilogy, Palpatine was able to so diminish his Force presence so that he could stand side-by-side with the most accomplished Jedi Masters, without their sensing anything was amiss. Incredibly, E.K. Johnston's novel Queen's Shadow revealed Palpatine even used the dark side in the Jedi Temple, confident he still couldn't be detected. There seems no doubt, then, that the mysterious Force techniques employed by the Sith could allow them to hide from the Nameless.
Did The Sith Create The Nameless?
This, naturally, leads to the possibility the Sith actually created the Nameless. Path of Deceit describes them as "unnatural," reminiscent of Palpatine's claim in Force predators like the Levelers, because their presence has a damaging effect on the Force itself; in Path of Deceit, a Jedi Knight was able to sense a void in the Force where a Nameless had fed upon one of his fellow Jedi. The Sith seek to dominate the Force, not to destroy it, so the Nameless would be a little too potent.
The Sith Could Still Be Using The Nameless
Path of Deceit is set 350 years before the events of Force power rooted in the dark side. The Nameless do not react to the Mother, however; if she is indeed Force-sensitive, then she knows how to hide in the Force, raising the possibility she is the Sith Lord of the High Republic Era.
The Jedi will be forced to go to extreme lengths to defeat the Nameless. They were first mentioned in Claudia Gray's novel Master & Apprentice, which revealed they are referred to in the Jedi prophecies that also foretell the coming of the Chosen One. "Only through the sacrifice of many Jedi will the Order cleanse the sin done to the Nameless," the prophecy reads, suggesting the Jedi's actions against the Nameless are a major reason the Force wound up out of balance. If this is indeed a Sith plot, then it shows how the Star Wars galaxy began to tilt towards the dark side.
