Grant Ward

Grant Ward is a S.H.I.E.L.D. field agent revealed to be a lifelong Hydra sleeper agent, recruited as a teenager by fellow agent John Garrett long before he ever joined the team he later betrays. Killed by Coulson in the third season, his corpse is immediately possessed by the ancient Inhuman Hive, who wears his face and memories for the rest of that season's story.

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