Eclipso
First appearing in House Of Secrets #61 in 1963, Eclipso is a villain apart – unassociated with any specific hero, and therefore free to cause chaos and mayhem wherever he pleases. He is essentially a vengeance demon – able to possess mere mortals at will. He is driven by the desire to recapture his more powerful days, and often seeks to possess super-beings, such as Captain Marvel and Superman, as well. His first host, however, is Bruce Gordon – a solar energy scientist who would then transform into Eclipso whenever there is an eclipse.
During the later story, Eclipso: The Darkness Within, the evil spirit is revealed to have once been bound into a large diamond in Africa, which was then shattered, allowing Eclipso to escape. This origin story makes Eclipso a villain that can reach into many universes and timelines – he next possesses Alex Montez, for example, when Montez purposefully absorbs most of the shards of Eclipso’s diamonds. Jean Loring – former spouse of Atom – is the following host for Eclipso after finding parts of the diamond in her prison cell.
The nature of Eclipso’s story means that he has crossed paths with a vast range of characters in the DC universe, including Catwoman, Constantine, Darkseid, Cyborg and Atom. The possibilities for this villainous character are endless.