Jeff Smith

Jeff was a boy who was possessed by an alien billionaire.

Biography
At the age of 6, Jeff was taken to see Isobella Havelstack where the mind of billionaire Terrence Malson was transferred into Jeff. At the age of 16 Malson would be able to take over Jeff's body however the Eighth Doctor showed Jeff how to erase his mind which would prolong Jeff's time in control of his body. Jeff eventually had enough of running from Malson's henchmen and shot himself in the head, seemingly killing Malson. (ST: Running Out of Time)