Kushana

Princess of Torumekia, youngest daughter of the Vai Emperor.
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 wipe the Sea of Corruption off the face of the earth, by any means necessary. While she is not presented as completely evil, she is definitely an antagonist.
In the manga, she has a much more complicated role, more of an antihero/ally than an antagonist. She is mostly driven by a desire for revenge against her father and three older half-brothers, whom she hates and blames for the fate of her mother. She commands the Torumekian Third Army, whom she trained personally; she is devoted to her men, and they are unswervingly loyal to her. Despite her ferocity in battle, she has a nobility of character that earns her the respect of both Nausicaa and Master Yupa. While she admires Nausicaa’s pacifist ideals, she sees herself as inescapably destined to walk the path of bloodshed.