Black Spectre - Carson Knowles

Courtesy of wikipedia:
The Black Spectre was Carson Knowles, a Vietnam war veteran whose father was a politician. Upon returning, he discovered that his wife left him and his son was killed. He couldn't get a job and decided to get revenge on the city since they turned his back on him when he needed it most. Inspired by Moon Knight, Knowles became the Black Spectre, a master criminal. He also decided to run for Mayor. Knowles was defeated by Moon Knight and sent to prison.
Knowles appeared again some time later, recently released from prison. He falls back into his ways as the Black Spectre and attempts to, yet again, destroy Moon Knight and hurt the city. Moon Knight ultimately pushes Knowles off a building to his death.