I do not own Stellaris or Gate - Jietai Kare no Chi nite, Kaku Tatakeri. That's it.

The Tellurian Empire, once it was nothing more than an early space age civilization with states vying for world domination for their home planet Terra. Year 2032, In the midst of a world war, numerous objects from the Alpha Centauri system were detected on a collision course for Terra; seeing as this is a possible extinction event, major nations had begun to devise their own plan to avoid such a fate. However, due to espionage, the nations discovered from each other their plans that involves usage of Weapons of Mass Destruction. The nations hastily concluded their enemies were planning to use WMD's to attack their own. Due to this, a war with many casualties wrought was unleashed, and the objects of Alpha Centauri loomed closer.

In the late stages of the war, the nations began to be exhausted and the objects were written off to collide or thrown off course with Jupiter instead due to it being close to its course. Many smaller and weaker nations had surrendered to stronger nations, some had began to isolate themselves, while others continued their domination. That was until numerous fireballs had appeared all around the globe and crashed into the ground causing damage to infrastructure and such, and out came extraterrestrials that look similar to humans save for several features donning futuristic armors and weapons. The Aliens wasted no time and immediately began exterminating life on Terra and began to strip mine the planet. The remaining nations of Terra eventually formed an alliance to fight off the Aliens and began sharing technology as well as resources to one another. After losing a huge percentage of the population, the aliens were eventually defeated, their technology and dead bodies taken for study and anything alive was enslaved and the humans having a new vigor for war, revenge. In light of this, the Tellurian Empire was born.

Extensive research into the alien wreckage has given humans advances in all branches of technology and science, 'Project Genesis', a project to genetically modify all of humanity with superior genes recovered from the humanoid aliens has gone into effect. In just 5 years, humanity has entered a golden age but knowing the threats of hostile extraterrestrials, they needed to ensure their peace is secured, and their peace shall be secured once they dominate the galaxy, starting by ruling over the aliens that had wronged them first.

The Hyperdrive was developed and the first starships were built, which designs had some inspirations from the humanoid aliens. First, humanity had scouted their home solar system and eventually the neighbouring systems. Numerous ship wreckages from what are most likely past space battles as well as ruined alien structures were discovered and studied, leading to further advancements. Eventually they met first formal alien contact with another alien nation known as the Korsal Principality, which started off with the Korals opening fire on sight, and the Terran ships, fire back. Eventually both had reached a stalemate and had a ceasefire. Formal talks were eventually made and discovered that the Korsals had mistaken the Terrans to be the Dovian, who were discovered to be the extraterrestrials that had invaded them. Seeing this, the Korsals had tried to negotiated a military pact with the Terrans to combat and aide each other against future Dovian attacks but was immediately refused due to Terrans developing xenophobia, especially with their first encounter being a literal invasion, however they were amenable to a non-aggression pact and a trading pact to which both had agreed on.

26 more years have passed, the Tellurian Empire has established contact with many more empires, some wars broke out with the Tellurian Empire victorious. Eventually they had entered an all-out war with the Dovian Purifiers. After over 13 years of war, humanity reached the homeworld of the Dovians and had the planet be destroyed from armageddon bombing. Humanity, with their thirst for revenge quenched, set their eyes on their original goal, securing peace through galactic dominance.

Once humanity was sure their military power far surpassed other empires and had evolved biologically, technologically and psionically, they had declared their intention to dominate the galaxy, demanding every other nation be their subject or perish. Many nations banded together as a federation to combat the Tellurian Empire, while some nations, mostly the nations on good terms with the Empire, had agreed to become subjects under agreeable conditions. Fallen Empires viewed this as nothing more than a young races tantrum and waved it off, watching as the galaxy prepared for war. Eventually war broke out with both sides taking heavy losses, nation after nation suffered losses that demoralized them, but for the tellurians, it just fueled them to fight harder. During the stages of the war, a sudden invasion from an extra galactic threat called the Prethoryn Scourge had arrived and immediately began devouring worlds. The nations of the federation placed much of their focus trying to fend off the scourge. Nations fell and empires crumbled, even the precursors known as the Cybrex were eradicated, the Tellurian Empire was being pushed back by the scourge and was forced to ally with the remaining nations of the galaxy.

However as if god himself was taking pleasure to the events happening, another extra galactic, or rather, extra dimensional threat had arrived. Calling themselves the Unbidden, they began attacking any worlds left and began devouring worlds for energy, eventually two more portals revealing the Vehement and Aberrant appear and began fighting each other along with the scourge. The empire saw this as an opportunity to rebuild and strike at their weak points undetected. However it was as if god still wasn't satisfied, and eventually the empires synthetics began to malfunction and leave the empire. The cause was found and stopped to find that an ancient AI that calls itself the Contingency had taken robots from all around and has awoken in light of the extra dimensional invaders. The remaining nations were at first relieved but that would all be shunned once the Contingency reveals to destroy all life, be it organic or robotic, from the galaxy.

As the 3 dubbed 'Crisis' factions were fighting each other, the remaining nations became subjects of the Tellurian Empire, even the fallen empires were no exception. With this the Tellurian Empire exploited everything from their subjects and whatever they could find. After studying the 3 crisis factions go to war with each other, many weaknesses were found. Eventually the Tellurian Empire was ready to push back the crisis factions and establish their own peace in the galaxy.

The Tellurian Empire scoured every solar system, purging infected worlds from the scourge, destroying extra dimensional anchors and obliterating sterilization hubs. Eventually, most prethoryn were killed while some were taken by the empire to serve them, the extra dimensional outpost linking the 2 dimensions closed with the remaining extra dimensionals either destroyed or captured. The Contingency Main Processor deactivated and isolated. In the end, the Tellurian Empire became the highest power of the galaxy and finally achieved their own peace, with the remaining extraterrestrial nations kept under a tight leash.

Much time would pass, along with that is peace. The empire slowly became more amenable to aliens and were eventually granted residence to the empire. The Tellurian Empire is the last nation in the galaxy and while they enjoy the current peace, they knew that just from the extra-galactic Prethoryn Scourge and the Extradimensional Invaders, their peace will not last. The empire continuously kept their armies ready at all times to defend the galaxy for any future galactic invaders to ensure the continued peace of the galaxy. However, a mysterious gate connected to a world from another universe opens up in the empires capital.

A/N: So uh yeah it's my first time trying to write a story, it's bad I know. I just thought of this for a while and my hands did this lol. Not really sure if I should continue this cus im pretty sure there are a LOT of discrepancies in this and I'm bad at writing.