Since youth, Jack trained in many different areas under numerous teachers in a variety of skills to defeat the demon Aku. However, Aku's dark magic sent Jack eons into the future, where he ruled all of Earth unopposed. Jack made it his mission to find a way back to his time and prevent Aku's dystopia. Throughout his travels, Jack became an infamous freedom fighter, protecting and aiding numerous civilizations and innocents terrorized by Aku's forces and other malevolent foes. Due to his many revolts against Aku's rule and being the only person capable of killing him because of his divinely crafted sword he was the most wanted man in the world.