The Battle of Sullust was a conflict which took place during the Clone Wars, a conflict between the Galactic Republic and the Confederacy of Independent Systems for control over the planet Sullust.
During this battle, Asajj Ventress commanded Separatist forces, but was targeted by Count Dooku, who wished to prove his allegiance to his Sith Master, Lord Sidious by killing his aspiring apprentice. Ventress was presumed dead in the conflict, but had escaped, while the Galactic Republic succeeded in its objectives with moderate cost.
Despite her past failures during battles on Teth, Rugosa, and Kamino, Ventress remained Count Dooku's most trusted and cunning assassin. However, his master, Darth Sidious, feared that she was being trained by Dooku to overthrow him, so that Dooku would become the master and Ventress as his apprentice. Dooku then sent Ventress to Sullust to battle.
Ventrss flies her starfighter during the battle.
In 20 BBY, Ventress and TJ-912 led the Confederacy navy against the Republic Navy under Jedi Generals Obi-Wan Kenobi, Anakin Skywalker, and Admiral Wullf Yularen. Ventress, in her Ginivex-class fanblade starfighter then led two groups of fighters in attacking the Republic's flagship, the Resolute. Trident group one attacked the starboard engines and Trident group two disabled the port shield generators. Using this opportunity created by the droid tri-fighters, Ventress was able to destroy the Resolute. Yularen was able to escape the Resolutes destruction.
Ventress and her fighters then pursued Kenobi and Skywalker in their fighters. Ventress pursued Kenobi while her fighters went after Skywalker. Ventress was then able to shoot down Kenobi and force him to land on the Separatist command ship. Ventress was then forced to crash-land on the command ship when Skywalker shot her down.
However, during the battle, Dooku was contacted by Lord Sidious. Darth Sidious told Dooku that he sensed a disturbance in the Force. Sidious suspected Dooku was training Ventress as his Sith apprentice to destroy him, and demanded that Dooku eliminate her to prove that the Count's allegiance was to him alone. Despite his objections of killing her, Dooku carried out his master's wish and recalled Ventress' reinforcements. Dooku then contacted Ventress, telling her that she had failed him for the last time and was no longer his apprentice and would die.
Ventress duels Kenobi and Skywalker.
Ventress then dueled Kenobi and Skywalker in the command ship's hangar. She was able to evade the Jedi's attacks until they force-pushed against her fighter. However, Ventress was able to force-choke them until TJ-912, under Dooku's orders, had her ship fire on the command ship to kill her. Hyena bombers along with the destroyer's cannons took out the Providences shields, exposing it to enemy fire. One bomber sustained heavy damage and crashed into the hangar. Skywalker and Kenobi then decided to flee the doomed flagship. Ventress barely escaped the cruiser's hangar before the ship was completely destroyed. However, her fighter's life support failed and she was left unconscious in her fighter. TJ-912 reported to Dooku that Ventress was killed. Dooku then ordered the tactical droid to withdraw from Sullust with what remained of their fleet.
Returning to Dathomir, Ventress reunited with the Nightsisters and sought revenge on Dooku.
Dooku then reported Ventress's death to Darth Sidious, who was pleased with Dooku proving his loyalty to him once again. Both Dooku and the Jedi Order believed that Ventress was killed during the battle. In truth, Ventress was found alive by Ratch's crew of the Raider. She was then revived by them and demanded that they take her home to Dathomir. When they refused, Ventress force-choked and killed them. She then took the Raider to Dathomir. There, she was taken by Mother Talzin and her Nightsisters where she recuperated by the Water of Life. Together, Ventress and her fellow Nightsisters planned revenge on Count Dooku.
Sidious and Dooku’s betrayal of Ventress at Sullust unknowingly set into motion a series of events that would ultimately lead to the return of Darth Maul, Sidious’ first apprentice, into the galaxy, leading to growing challenges for the Sith and their plans for the remainder of the war.