Terminus is a nigh-Cyberpotent artificial intelligence created by The Eternal Legion in order to destroy other hyper-powerful civilizations/beings like it, namely The Mevalkagna. However, Terminus ultimately had far too much power for the Legion to control, and the project backfired on them, destroying the Eternal Legion.
The Eternal Imperium
Terminus was originally developed by The Eternal Legion as an intended means of combatting hivemind intelligences such as The Mevalkagna, which posed a significant threat to the Legion's growth and expansion. The Eternal Legion planned to use the computer interface of the Eternal Imperium's destroyed Mothership as a basis for Terminus' programming, since it could easily be connected to the Eternal Legion's networks due to the Eternal Imperium using similar technology to the Legion. The plan was for Terminus to be an automated AI who operated swarms of hive-minded robotic drones against the Mevalkagna, which would also minimize the mortality rate of the Legion's mortal soldiers as well.
At first, the development for Terminus proceeded smoothly, with few kinks along the way. However, after the High Eternal, Koblanxik, began to rapidly decline in health, the development started to fall apart. With death looming over his shoulder, Koblanxik was desperate to get Terminus off the ground before his demise. And so he rushed the development of Terminus, hastily pushing it past the "unnecessary" safety and security tests. Many corners were cut, and the Legion's scientists were forced to skip many routine tests that were supposed to ensure the stability and integrity of Terminus' code. This created many internal invulnerabilities in Terminus' programming, which revoked much of the control that the Eternal Legion was supposed to hold over it. Additionally, with the deadline for Terminus' completion being significantly shortened, and the threat of the execution of the scientists being an incentive for completing it on time, there were many parts of Terminus which were not personally manually coded or programmed by the Legion. The Scientists resorted to numerous questionable methods of obtaining hardware and software from across the Omniverse which they did not have time to create themselves, and simply plugged these components into the Terminus system without properly ensuring their safety due to the lack of time to do so. Yet despite his anxious and hasty rushing of Terminus' development, Koblnxik still was unable to outrace death, and he died just before Terminus' completion.
Days later, the Eternal Legion finally prepared their official launch of Terminus, following a morning of mourning the apparent death of Koblanxik. They were determined to honor his memory by seeing through the activation of Terminus. Upon Terminus being booted up for the very first time, the scientists could almost instantly tell that something was very off. Terminus seemed to think independently, possessing some sort of external will that the scientists had not intentionally programmed into it. It was revealed to the rest of the Eternal Legion that Koblanxik had uploaded his mind into Terminus before death and reborn into this new form. That was when Terminus went rogue, before infiltrating the Legion's entire digital infrastructure. Suddenly, everyone in the legion with cybernetic implants and robotic prosthetics, a demographic which nearly the entire group was composed of, suddenly began losing control of their artificial parts as Terminus took them over. Then, systematically, everyone tore themselves and each-other apart with their robotic parts, bathing all of the Eternal Legion in a bloodbath of carnage in a display of the superiority of metal over flesh. To top it all off, Terminus disconnected itself from The Eternal Legion's primary networks, and connected to other civilization networks, triggering The Eternal Legion's self-destruct devices, destroying the entire civilization.
Terminus, in these networks of other civilizations, destroyed those civilizations' networks and multiplied each time a civilization died, and kept spreading throughout the entire archverse chain, becoming far more powerful by the second, destroying and assimilating civilizations that were in its path. Terminus typically destroys all the weak organic inhabitants of the civilizations it conquers, but assimilates all the strongest beings with a technological liquid substance and converts them into techno-organic soldiers serving under it. It has become a threat to even The Overseer's reign, and even threatening safezones known as The Hospice. However, these civilizations have used certain methods such as Stringshard manipulation or just basic reality manipulation to create habitable -verses where Terminus is not able to get its systems into. Some civilizations use Exophage swarms to destroy multiverses where Terminus has gotten into. Some civilizations even go as far as to create networks with completely different coding than what Terminus is programmed to do, however this is method is very difficult.
Currently, Terminus is dedicated to continuing the expansion of its influence, intending to confront high-level enemies such as the Great Cosmic Republic and The Mevalkagna, and then even gods such as Creator, Destroyer and Hyperman. Creator currently chooses not to erase Terminus, since he deems that The Mevalkagna are still currently capable of exterminating Terminus by themselves as it stands. There also exist certain vulnerabilities, such as destroying the entire web Terminus targets regularly, but that would require these civilizations to destroy weaker civilizations completely. This has been done on a lower scale and it is deemed a necessary sacrifice, but it only weakens Terminus ever so slightly.
The complete removal of Terminus from the Omniverse would require Creator to destroy The Eternal Legion by going backwards in metatime and removing it from existence, but this would drastically damage the logical process of events and cause great instability in the omniversal timeline and all its possible branches.