Darkseid - JLA: Rock of Ages
In JLA: Rock of Ages, The Flash and Green Lantern Kyle Rayner are teleported 15 years into the future where Darkseid has possession of the anti-life Equation and has taken control of both New Genesis and Earth. The heroes scour the planet for traces of their heroic allies only to find that Superman is dead and Batman has been captured. They find evidence that Darkseid has held his power over the people, maintained by a broadcast of the anti-life equation, for over a decade.
The two heroes go back in time to correct the events that lead to Darkseid taking power but... Darkseid did it! He won! Darkseid killed his greatest enemies and fulfilled all of his goals. If it weren't for The Flash and Green Lantern's random ability to time travel then the DC Universe would still be under Darkseid's control.