Bruce Gordon(DC, from Eclipso)

Bruce Gordon is Earth's leading Solar Energy scientist. While on an expedition to view a solar eclipse he was wounded with a black diamond, which enabled Eclipso, a vengeance demon, to possess Gordon's body at the sight of an eclipse. At some point, any naturally occurring eclipse would cause Gordon and Eclipso to split apart into separate entities, while an artificial eclipse would allow Eclipso to control Gordon's body. Any bright flash of light would undo the change.