Who he is: Johann Fennhoff, better known to comic book readers as Doctor Faustus.
His power: Hypnotism, usually based around manipulating a person into hallucinating that they’re doing one thing while they’re actually doing another.
His story: As seen on Agent Carter, Fennhoff was a soldier in the Soviet army during World War II, and he fought in the so-called Battle Of Finow that saw the U.S. military secretly deploy Howard Stark’s Midnight Oil biological weapon that drove everyone involved to brutally murder each other—everybody except Fennhoff, that is. He was later enlisted into the Soviet spy agency Leviathan, and posed as a prisoner when Agent Peggy Carter raided a Leviathan installation. He was taken into SSR custody and pretended to help in the organization’s investigations into Leviathan, but in reality he was trying to obtain the Midnight Oil and take revenge on Stark.