“Look out, everybody, things are about to get awesome!”
Xylourgos is an icy planet located in the farthest reaches of the galaxy, overshadowed by an eternal eclipse. On the surface of the planet lies Gythian, a deceased Vault monster whose heart still beats on even after death.
In the distant past, the Eridians used the planet of Xylourgos to imprison a unique Vault monster named Gythian, who possessed the power to influence the hearts of others and grant eternal life to those under his control, though at the cost of their humanity. Gythian would be locked away in a Vault on the planet's treacherous mountain pass of Negul Neshai, though Gythian would somehow escape his prison. By unknown circumstances, Gythian would eventually be slain, his body now lies dead on the surface of the planet. Despite this, Gythian still lived on as his heart continued to beat, even as his physical body laid dead, and began influencing the world around him with his mysterious powers.
Around the time when the Atlas corporation made its findings of Eridian technology within a Vault on Promethea, the Dahl corporation began its own universal search for other Vaults to further their own success and corporate dominance like Atlas. A Dahl research team under the command of Eleanor and Vincent Olmstead would travel to Xylourgos to research Gythian, whose legend vastly interested the Olmsteads. The research team would conduct various research on Gyhtian's physiology, as well as the mutagenic and metaphysical properties of his power, hoping to discover new xenobiological revelations that would change the universe. Upon investigating the Eridian ruins at the former site of Gythian's Vault on Negul Neshai, the Olmsteads would discover the same Eridian technology found within the Vault found by Atlas, and Vincent would find a connection to Gythian's power and the Eridian technology, wishing to experiment with this discovery further.
Vincent's experiments however would lead him to slowly fall under Gythian's influence, driving him mad and influencing him to sacrifice his humanity in exchange for eternal life. Now completely obsessed with power, Vincent would travel alone to Gythian's heart chamber, only to be entombed within the heart itself; Vincent however would remain alive, but was now unable to leave his bonds physically. Eleanor, who was too late to stop Vincent, began devising a plan to free her beloved; using Vincent's research on the connection between the Eridian technology and Gythian's heart, Eleanor forged two rings from the Eridian technology and began work on refining a sample of Gythian's heart she recovered by utilizing their research ship's reactor. Upon finishing her work, she infused the rings with the sample of Gythian's heart, and upon putting one of the rings on her own finger, she too began to become influenced by Gythian.
As she was considered half of the bond, she needed one more to wear the other ring intended for Vincent, which would draw out his mind from Gythian's heart and into the wearer of the other ring. Upon placing Vincent's ring on the finger of her fellow crew member Harrington, he was soon possessed by Vincent, who used his body as a new vessel while his original body remained within Gythian's heart. However, the bodies Vincent would possess would only last for so long before dying, forcing the Olmsteads to form a scheme to lure people to Xylourgos to supply Vincent with more vessels. Revealing Xylourgos to the rest of the universe, the Olmsteads drew countless researchers, tourists and various others to Xylourgos and their newly-created town, where they are subjected to Gythian's influence by the Olmsteads. The Olmsteads would then form the Bonded, a cult-based following who worshiped Gythian, and would act as the many vessels that would be supplied to Vincent. As for the remaining inhabitants of the town, they would become cursed by Gythian's power, gaining abnormal traits and uncontrollable powers.