Who he is: Edwin Jarvis
His power: No superpowers, but he’s an attentive butler, a good friend, and has a little bit of martial-arts training.
His story: As seen in Marvel’s Agent Carter, Jarvis was a member of the British military before and during World War II. He met his wife, Ana, but was dishonorably discharged when he forged a general’s signature trying to help Ana escape from the Nazis. Luckily, he had befriended Howard Stark at that point, who brought Jarvis and Ana to America and gave Jarvis a job as his butler. Years later, when Stark was working with SSR Agent Peggy Carter to recover some of his stolen inventions, Jarvis was enlisted to assist her in any way necessary. His familiarity with Stark and Stark’s work made him a valuably ally, as did his overall charm and friendliness. One of the stolen items Carter and Jarvis recovered was a vial of Steve Rogers’ blood, which Jarvis gave to Carter after the two of them stopped Johann Fennhoff from using a hypnotized Stark to destroy New York.