Dellex was a female cyborg who served as a Storm for the Nihil marauder organization during the High Republic Era. She always thought of herself as ugly and because of this, spent all of her money on shiny mechanical upgrades to make herself more beautiful. She had worked under Kassav Milliko and his Tempest for a long time, with Kassav even being attracted to her at one point despite her perceived ugliness. He noted that her upgrades did not do her personality any favors and regarded her as a dangerous person.
She served in Milliko's Tempest on several occasions in 232 BBY, including a mission at the planet Eriadu in an attempt to extort their government by saving them from the Emergence of hyperspace debris from the Great Hyperspace Disaster. However, they accidentally allowed the Emergence to contact the planet, causing tremendous casualties. The Eriaduans swore revenge on Milliko and his crew. Dellex would later participate in the Battle of Kur, facing a joint task force sent by the Galactic Republic and the Jedi Order, in addition to a flotilla of Eriaduan cruisers. Although the Nihil employed a devastating array of cruel tactics at the battle, they were ultimately routed by the Republic forces. She was one of the last survivors aboard Milliko's flagship, the New Elite, when it was boarded by Eriaduan soldiers, who took their revenge by killing all aboard.