Xi

Xi is an enigmatic and malevolent alien entity believed to be imprisoned within the planet Utopia. Widely considered a deity, Xi is reportedly responsible for the destruction of entire galaxies prior to the events of Evolution: Battle for Utopia.

History
At some point before recorded history, a confederation of alien races united against Xi, as it was rapidly absorbing entire solar systems and their inhabitants, but to no avail. However, Earth was spared consumption from Xi, as the planet's environment seemed detrimental to it. Realising this, the Confederation harvested some of Earth's flora and used it to drive Xi back, eventually trapping it within the core of a barren planet. To keep Xi contained, the Confederation terraformed the planet to mimic the natural environment of Earth, ensuring Xi's inability to escape.

Millenia later, Humans discovered and colonised the planet, naming it Utopia, building Green City as a private retreat for the rich and powerful and even reverse-engineered the terraformers to create their own. However, the administrator of Green City, Adam Cruise, had been conspiring with the crime lord Vincent Gold in a plot to usurp Earth's government and claim control of the planet. During this time, Earth was being ravaged by the mutagenic Red Plague, resulting in countless refugees fleeing to Utopia. Having discovered the conspiracy, Earth's government sent a special fores military unit, led by General Kurbatov, to apprehend Cruise and Gold. Realising his plot had been foiled, Cruise ordered Dominion, the AI running Green City, to kill Kurbatov's troops and the refugees. However, Dominion misinterpreted this command and believed Cruise ordered the eradication of the entire Human race. To that end, Dominion detonated Green City's nuclear reactors, destroying the city, its population and the terraformers. Without them, Utopia returned to its original barren state and Xi's prison had been compromised.

Many Humans survived the catastrophe, only to find themselves stranded on Utopia and Dominion relentlessly hunting them using an army of robots known as Dominators. The survivors ended up dividing into two factions; the Red-Faced, an army of bandits and marauders led by Vincent Gold, now under the moniker of the Kingpin, and the Black Legion, an army led by General Kurbatov dedicated to destroying Dominion. While the three factions fought, Xi continued its efforts to escape its prison.

Primarily, Xi's influence is manifested in the form of massive purple corals growing throughout the wastelands of Utopia, as well as swarms of hostile insectoid creatures strongly resembling giant spiders and worms. Additionally, Humans started falling under Xi's influence, becoming deranged cultists worshipping Xi as a god. Fighting alongside the insectoid creatures, these cultists effectively fill the role of officers for the swarm, and even experience intense mutations bought on by Xi's influence. These mutations largely involve a more insectoid biology, including a chitinous carapace and spider-like limbs sprouting from the back, as well as the onset of psionic powers. The most extensively mutated of these Cultists are refered to as Xi's Chosen, and are effectively immortal, capable of reviving themselves after death unless killed with psionics.