A black market weapons dealer in possession of stolen S.H.I.E.L.D. technology. He is captured multiple times but escapes using a flash-emitting cellphone function that temporarily brainwashes the Punisher. He is ultimately tracked down and killed by Punisher in Miami after the main mission concludes.
Widow actively hunts Cain as the primary lead to the stolen technology plot.
Both are integrated into the same terrorist network facilitating the technology sale.