Ferus

"I can sense the taint of the Dark Side, here. Let us leave this place... forget about this, forget the quest."

- Zan Fyar to Cadden Blackthorne

Ferus was a world located within the Unknown Regions. Little was known about the world, other than the fact that it once held the resting place of Rahk'neqah's Soulblade, which was guarded by Jedi spirits. How the weapon got on the planet, and who put it there, remained a mystery, though it was speculated that the Nomad Soul did it himself, or had a hand in it, in order to eventually lure his unwitting host to the location.

The planet itself seemed to be corrupted by the dark side of the Force, as noted by Zan Fyar when he accompanied Cadden Blackthorne to find Soulblade, the source of power promised to Cadden to help him kill Sivter. However, the Jedi spirits guarding the blade did not seem affected by its corruption, noting that they were trying to defend Blackthorne from the blade, not the other way around.

At some point in time, whether it was before or after Fyar's and Blackthorne's visit to the planet, rodians set up a colony on the world, in order to scavenge the remnants of a lost civilization they discovered. It was unknown if whether or not became corrupted by the taint of the dark side.

Behind the Scenes
Ferus is taken from the latin word of the same name, meaning  fierce, wild, savage, untamed.