Nick Tesla is a KORPS agent.
An accident occurred at STERNUM's heavy extranium reactor, causing the works, including Tesla to age. He was imprisoned by KORPS, along with the other aged STERNUM operatives. They were registered as their own grandparents and placed in a old people's home, run by KORPS, where they were kept prisoner.
Registered as Hubert, his grandfather, Nick received a visit from the MI High team. He eventually gave them the location of the heavy extranium reactor, after the team broke him and the other prisoners out.