A scientist with a variety of interests. Probably not insane.
Dawson, Silas, and Pelleon originally met Sebastian in Milwaukee. Sebastian was being held captive by a group of raiders who forced him to cyberize them extensively. Those raiders attacked a caravan that the party was guarding and were killed. A short time later, Sebastian appeared and hitched a ride to Trenton. He has since set up shop there as a doctor, inventor, and expert in prosthesis.
From time to time, Sebastian has called upon the party to retrieve items of interest for him from abandoned labs he used to work in. The labs have not always turned out to be abandoned once the party got there.
Sebastian is rarely seen out of his lab without Leonard. Leonard is a ten foot tall cyborg with a low IQ. Though Leonard is mentally deficient, he can move very quickly when provoked.