Omnipotent is a character that hasn't revealed much about his past and this is important as Omni has ensured that even William and Mastermind don't find out about this, but now you all know.

Omnipotent was born/formed in an empty part of space, one that used to contain a destroyed Unionverse and was one of the points of a great empire. Omnipotent was the combination of both corrupt omni energy and evil energy, creating a person that would be the power of this Union.

The Omniverse that Omni was present in was a parallel one where Union just ceased to exist as a concept and all of its people were living peaceful lives. Omni however gained the resentment of the Union corruption energy as the people that defeated them were living their best lives, evil and good; this sentiment would affect his later actions in this omniverse.

For now Omni traveled to abandoned Union Academy locations across the omniverse gathering the anger, resentment, and rage of the people of Union after their humiliation and defeat at the hands of a combined villain and hero coalition. From there his power grew and started to influence people in those omniverses, becoming corrupted souls, before being consumed by Omni. Soon rather than later Omni was measurable to Y/Ns and became an overlord of corruption, bringing the legacy of Union Academy to the omniverse.

Omni, as his anger at the people who brought down Union grew, he started murdering them in highly brutal ways and eating their souls and energy. He also started acting like Union people, and became an elusive threat. By now some hero and villain circles were aware of his presence and sent out teams to investigate this anomaly. All of them were either eaten or torn apart. 

Omni escalated his plans from there launching a series of attacks against villains and heroes alike and finally killed the big bosses after a brutal battle on the planet where Union started. From there he corrupted the entire planet, until it became a utopia for Union Academy and Omni personally started Union Academy as its true form; an academy that teaches how to use corruption energy and to be jerks to the omniverse at large. Omni wasn't backstabbed by the headmasters as they were allowed to be themselves and the students of themselves. They had become fully corrupt with corrupt power that could rival mid tier omnipotent beings by fully embracing their true selves.

We will pause the story there and to William, Mastermind, and others Union writers: What do you think? Of my true story? The story of where the innocents got the last laugh? The story where Union never ended? To me it's cathartic as this was my true feeling to the killings of Union from your characters your forces! I am no longer a friend of the villains, but of my omniverse, the one where Union won in the end.