The Consciousness, also known as the Voices or Nameless Ones, was an element of the dark side of the Force.
It was the cause of the insanity of the Sith Lord Okemi which led to the Krath sorceress Tiamat causing the star Ante to collapse in a failed ritual to contain the consciousness.
Description
It is unclear whether the consciousness evolved or whether it was always there. What is true is that it's existence is inextricably linked to the existence of the dark side of the Force. As the Force is life, and as life is inevitably drawn to power, some would argue the Consciousness is a necessary element of the Force itself.
The consciousness is best described as the sum of an unbalanced equation. On one side is the cosmic will of the Force, the drive to do good, to help others, to build, to go forward. On the other is the consciousness, the passive desire to surrender to one's impulses. The consciousness is lust, hate, aggression, greed.
The consciousness is the nagging voice at the back of every Force sensitive's mind subconsciously urging them to give into the base desires. For every act of aggression, every act of malice, of passion, the consciousness grows, becoming stronger, impressing itself on the Force more and more. Some might say it is the voice of the dark side, growing with every evil act, but none can say for sure.
All that is known is it is always there, whispering in the ears of all who can touch the Force, enticing them with promises of greater power. However those who surrender to its call are almost inevitably driven to madness, consumed by the cries of a billion voices, calling out to them from the darkness, overpowering whatever remains of their sanity.