Fei Roshnante is a FromSoftware original character in Another Century's Episode 3 THE FINAL.
In World B, she used to work under Berkt. Once she found out Berkt's true goals, she tried escaping, but got seriously injured by Berkt's forces. She was rescued by Jill Bardona, and managed to escape to World A along with the Ixbrau.
Once there, she met Barrel Orland, and piloted the Ixbrau with him. After their final fight with Berkt, Barrel realized he was the key to saving the two worlds, and was going to go off on his own. Fey went along though, claiming she had a plan, but she had no plan and just wanted to be with him until the end.