Nine is a major alternate-dimension version of Tails from Sonic Prime, reimagined as a lone, cautious, and highly intelligent inventor. He is a fox with nine tails who has built advanced technology to survive in the Shatterverse after being separated from Sonic and the others. Unlike the friendly Tails, Nine is initially distrustful and defensive, serving as both an ally and an emotionally complex rival to Sonic. His role in the series is central to the conflict around the Paradox Prism and the fate of the shattered worlds.