Era 8 Sukallion Vanz (VIII): Super Survivor + Finish 'Em Off by Hironobu Kageyama (played simultaneously). Reflected the dual aspects of the character, both before and after 20 years of his life had been effectively removed from him.
Era 9 Clone Fighter IX ("Kyuu"): To the Future Pointed By the Light by Hironobu Kageyama. Started off lighthearted enough as a dumb kid so the song fit him until he learned more about what he actually was.
Era 10 Sukallion IX (Altered Timeline): Turn on a Light Inside the Smoking Heart by Hironobu Kageyama. Basically in the same vein as Kyuu's, very upbeat and singing about how he loves to fight (and without any dark horrible secrets of his origins or whatever).
Era 11 Sorrel: Pirate Song by Alestorm. Sets the tone of a former feared pirate who dwells on what he had lost.