Vul Isen was a Force-sensitive Givin male who served the One Sith as a scientist. Born into the One Sith on Korriban, his talents did not lie in combat, but in science, so he was never given the coveted "Darth" title. Isen worked extensively with bioweapons, and was experienced in committing genocide and ruining planets with such toxins. He found no sorrow or regret in these actions, thinking of it as a sort of game.