Omnusali

The Omnusali are a faction of malicious, malevolent forces led by Grimmok and O.M.N.I. during their campaigns of the Maelstrom War, Reborn Maelstrom War, and beyond, and consist of powerful entities that seek the corruption and destruction of all living beings on Outhria, and to an extension, a great degree of the universe - the Almighty Expanse, with the powers they have obtained.
Long before the Maelstrom War began, Grimmok and OMNI, both devout, but suspiciously powerful individuals, made a bargain in secret with an unknown entity, transforming them into extremely powerful beings, and nearly damning their races (the Drakkin and the Akrin) to extinction. Since then, their efforts have resulted in the destruction of several strongholds and landmarks, the corruption and killing of many forms of life, and even causing time and space to repeat themselves, albeit with different consequences and actions unlike the past, forcing the hand of the Primearch, resulting in a Primearch Rupturing.
During the Maelstrom War, Grimmok and OMNI were defeated, retreating into the Maelstrom from which they enacted their schemes to recuperate. While down there, they forged a flying base, Omegaheim to stall the advance of champions who understood their next scheme, while they fuddled with the Paradox Equation to break into the Godvault. After Omegaheim's destruction, Grimmok and OMNI obtained a Paradox Orb, using it to make the Great Turnback. After a lengthy campaign, the two were defeated again, and finished for good, resulting in a crippling blow to the Omnusali. Because of their actions, they are considered to be one of Outhria's most feared enemies, and its main nemesis, as they have changed the events of the world forever. However, it remains to be seen, as some fear, the Omnusali are only a "fraction" of some bigger, more evil faction.