Nowhere on Korriban is the planet's dark influence stronger than in the lower wilds. What begins as ringing ears and a cold unease can eventually cripple and dominate an unprepared Sith; weaker minds can be twisted and broken in a matter of hours, leaving soldiers weeping in the sand or slaves frothing, ready to kill.
The source of this corrupting power is unknown. Some believe it is the residual dark energy of the ancient Sith species, while others insist the canyon serves as a focal point for the combined hatred and strength of the entombed Dark Lords. Some even hope the madness is caused by an artifact buried beneath the sands, waiting for a Sith to claim its power.