Enoch

Enoch is a Chronicom -- a member of a robotic alien species -- who defects from his own people to help S.H.I.E.L.D., guiding Fitz across seventy years of cryogenic stasis to reach the team in the future. He sacrifices his own mechanical heart to save the team from a time storm in the show's final season.

First turns up in Agents of S.H.I.E.L.D. (Season 5).