Guardsman (comics)
Guardsman was the name of a supervillain/superhero in the Marvel Universe, but the name was later applied to a small squad of agents. He/they wear suits of power armor while working security at the Vault; the suits were designed by Tony Stark, better known as the superhero Iron Man.
Read more about Guardsman (comics): Guardsman (Kevin O'Brien), Guardsman (Michael O'Brien), Powers and Abilities