Dark Energy is the insane Oracle Deity who caused most of the deaths of the other Oracle Deities.
Rise to Power
Little is known what the other Oracles saw in him, but being the youngest of the Oracles, Dark Energy had the shortest temper, he would often go on execution massacres, executing people left and right whom did not please him.
Assault on Earth
Dark Energy was against this, but Malice did it anyway, Malice enjoyed angering Dark Energy. The angry Oracle then began assassinating other Oracles, attempting to make himself de-facto leader of the entire Zodiac.
When The Zodiac split, Dark Energy found this a perfect time to finish off what he had started. He ushered the remaining Oracles to flee to The Mantle and set up base there, how he found out about this Mantle is debatable, but the most plausible reason is that The Metatron told him about it. Dark Energy then gathered them all in one chamber and destroyed the building they were in on The Mantle.
Escape to Atlantis
Dark Energy, unlike the other Zodiac, wanted to control Haven, not destroy it. He fled to Atlantis on Earth once the portal opened and activated it. There, he was driven insane by The Metatron who told him about how everything he believed in was a lie.
During the Reformation, Dark Energy was pesecuted and exiled because of his acts. He was reduced to the life of a street bum and everywhere he walked people made fun of him and threw stuff at him, especially his fellow Oracles who believed he had disgraced them.