Devlin Levin is the future son of Kevin Levin, so as for the alternate Kevin's future alter-ego, Kevin 11,000, who appears in the future timeline episode of Ben 10 franchise.
He is voiced by Charlie Schlatter.
History
Devlin has never been truly evil; he's just lived in the Null Void of Saturn since childhood. Since his father was captured again and his mother's fate is unknown, Devlin developed the same powers as his father, eventually becoming as strong as him.
Devlin eventually manages to contact his father, who urges him to trick Ben 10,000's son, Ken Tennyson, into returning him while he was trapped in the Null Void. Despite Devlin's plan, he becomes genuinely friendly with Ken, and even when he succeeds, he feels guilty, especially when he discovers that his father was more interested in getting revenge on Ben and all the Tennysons than being with him, greatly upsetting him.
Devlin tries to gain forgiveness by trying to stop his father, and in the end, Kevin is locked up in a cell. Devlin feels sorry for him and even fears he'll suffer the same fate. But instead, Ken and his father allow them to become part of their family. Devlin happily accepts. Devlin will find his father changed in the future and forgive him.
