Sebastian J Willberforce works for MI9, who appeared in Old School.
Sebastian invented a machine that can upgrade MI9 technology, resulting in MI High being disbanded. However, the weapon was hijacked by Jemima Thursday, and she set it in reverse, rewinding technology to previous versions of itself. The MI High team were reinstated and Sebastian's invention discarded.
Sebastian was very rude to the MI High team, despite not being much older than they were. He also had a comfort blanket, although he constantly claimed it was a picnic blanket.