Kushana is an Imperial Princess of Torumekia and the step-daughter of the Vai Emperor.
Kushana is the child of the predecessor to The Vai Emperor, who married her mother after coming to power. She grew up closer to her mother, due to the cruel and strict lifestyle of the Torumekian Royal Family with her relations to the previous king being a major source of their scorn. Her mother suffered and ended up in a mentally unstable state, for which Kushana partly blames her half-brothers due to a poison that she was tricked into ingesting. She is trained as a military general and inspires great loyalty. She trained the Torumekian Third Army personally and is very devoted to her men.
When a God Warrior is found in Pejitei Kushana is sent to invade the nominal Torumekian ally. She successfully captures their city and secures the God Warrior, though Princess Rastel escaped with the control stone, which can control the dormant Warrior. While she is in Pejitei, Kurotowa, a new advisor sent by her father, arrives. After initially trying to have him assassinated, Kushana learns to value his knowledge in strategy, though she still questions his true loyalty. Her brothers task her with finding the control stone, which Kushana tracks to the Valley of the Wind. There, she meets Nausicaa, who tries to get Kushana to leave the valley.
Torumekia declares war on the Dorok Principalities and Kushana invokes the ancient treaties by which the Periphery states are bound. The Valley of the Wind send their gunship to an aerial rendezvous point, where they are joined by other Periphery state ships. Kushana plans to fly across the Sea of Corruption into Dorok lands to join the war, as ordered by her brothers. Near the rendezvous point, however, their fleet is attacked by Asbel of Pejitei. Eventually Asbel is shot down by Kurotowa, but not before Kushana loses several ships, including the Valley of the Wind ships.
Kushana lands at the Acid Lakes and sets up base. The Valley of the Wind brig rejoins them after being rescued by Nausciaa, but Nausicaa herself is still missing. Kushana grants Mito permission to look for her. Unbeknownst to her, Kushana's brothers betrayed her position to the Doroks and a Dorok attack was imminent. A Dorok fleet appears and engages Kushana's forces. She soon suspects a trap however, since they are too weak to attack in broad daylight. Nausicaa, who escapes from captivity by the Mani Tribe, discovers that the Doroks are leading thousands of Ohmus to the Acid Lakes. Most of Kushana's forces are destroyed, but Kushana herself manages to escape.
After the Battle, the Valley Gunship returns to the Valley of the Wind, but Nausicaa decides to accompany Kushana on her invasion of the Dorok principalities. Kushana crosses the southern part of the Sea of Corruption and enters Dorok land. She flies over the province of Sapata, where she seeks out the Torumekian Thrid Army. They pass a village where disagreements arise, resulting in a confrontation between Kurotowa and Kushana. Kushana says that Kurotowa is on a mission from her brothers to have Kushana die and find the control stone. Kurotowa then decides to switch sides, as he guessed they would have killed him anyway after the mission, as he is not nobility. He analyzes correctly that she is trying to find her Third Army to overthrow her father and offers to help.
Kushana finds her Third Army almost entirely destroyed as they were deployed in dangerous positions on purpose by her brothers. The Dorok armies have overwhelmed Torumekian troops due to their use of miasma as a bio-weapon. She picks up the last two survivors from one of the divisions and heads to the Sapata city-fortress where one of her brothers' generals is under siege. The general is about to flee when Kushana arrives. She is welcomed by her former General Senei. Nausicaa asks Kushana to release prisoners she has taken and she agrees if Nausicaa fights for her in battle. They go to battle and manage to pass enemy lines, though they are eventually beaten back. Nausicaa then releases the prisoners and leaves Sapata.
The Dorok forces are forced to retreat to make way for Mirapula's new bioweapon. The Dorok soldiers release miasma on the unprepared Torumekians and kill most of them. Kushana manages to survive, but one of her brother is killed by insects. She is suprised how easily he died, since she has been using the hatred of her brothers as a motivation for a long time. She surprises herself by singing in the trenches.
In the anime, she lost one of her arms as a child during an Ohmu attack and is driven by a desire for revenge against the giant insects. She intends to destroy the Sea of Corruption by any means necessary. While she is not presented as completely evil, she is definitely an antagonist. Her motive is that when she was a child she was attacked by an Ohmu and her arm and both legs had to be amputated. She had to grow up with a metal shell as an arm. Although at times she appears to be mean and cruel, she is actually very afraid. She puts up a strong front in order to hide her fears and actually has a very caring heart. As the story unfolds she changes into a gentle and more caring person. When Mito returns to the Valley, she orders her troops to stop firing at him because she was worried about Nausicaa's safety. So even though she led the invasion of the Valley, Kushana is not a hateful character. Her plight generates sympathy, and her goals and ideals are understandable. She could not have predicted the results of her actions and did not do anything out of cruelty.
In the Legacy of Chris Thorndyke,
And she is reprised by Uma Thurman in the English dub and Yoshiko Sakakibara in the Japanese dub.