Deathlok

Mike Peterson is a day-laborer secretly enhanced by the black-market super-soldier program Project Centipede, then rebuilt against his will into the cybernetic soldier Deathlok. He turns on his captors to save Coulson's team in the first season, then leaves to seek redemption alone, unable to face the son he'd been fighting to protect.

First turns up in Agents of S.H.I.E.L.D. (Season 1).