Darker

The Darker was a being composed entirely of the hate, anger, fear and other negative emotions of the Arbran species, who purged their bodies of such ill feelings before leaving their homeworld Arbra behind to start anew. Their dark energy manifested into the Darker, a creature that had the ability to instill negative emotions in other beings, but was kept trapped within an ancient city with a force screen. In 3 ABY, the Rebel Alliance established a major base on Arbra, a development that the Darker attempted to use to his advantage to escape. However, after luring several Rebels into his lair, the Darker was killed by the Wookiee Chewbacca, who overcame the Darker's powers with the help of the droid C-3PO and several native Hoojibs.

Text and facts from the “Darker” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.