The war started off as a seven year losing period for the allied forces before the TEC and Kaiser Matt Tygore began pushing the Oya back.
The Oya Conclave (a religiously themed empire/confederation of races) was founded in 419 CE twenty years after "Barojakk's revelation" the conclave began conquering and forcefully converting hundreds of species across the Osian and Pavonis Sectors, only being resisted by the Liskan Democratic Republic who still had lost 75% of it's population.
by 1771 CE the Oya Conclave had conquered the Hedgie Amilate an ancient 19,000 year old Empire, however a five way split in the interpratation of their religion began in 1795 that led to centuries of civil war until 2455 when Etille En'Lile took power and wiped out the other sects in the "Five Keys War"
After the conquest of Atladil in 2495, the Oya had full control of the Osian sector aside from one planet, where their soldiers never returned from, they sent a 4000 ship strong fleet to conquer the world, days later only a third of that fleet survived, and were chased by something called "Jinyehudani" that pursued the fleet through a desperate warp rift which led the fleet and the Jinyehudani to planet Sangerrika in 2496 through its star beacon.
This eventually led to the Kanderarch incident, as the Oya Conclave licked their wounds and attempted to figure out what had transpired.
By 2599 the Oya Conclave had built up their military and set their eyes upon the Centerpoint controlled sectors, the invasion was to begin in the very next year.
Oya Invasion 2600
The Oya Conclave began their invasion of the other eight sectors, catching everyone by surprise, within 7 years the resident factions had been defeated and it's people enslaved although insurgencies continued for Five years during it's occupation, they accomplished little.
Fall of Earth
Months earlier the Kaiser and others had working on the Centerpoint defense system, soon after UTSEA space was attacked by the Oya Conclave, at the battle of Roma, the UTSEA Fleet was wiped out, and months later the Earth defenses were demolished, the Kaiser himself along with his elite guard warp-rifted to the Pavonis sector, as the Earth and the UTSEA fell to the Conclave.
The Great Conversion
The Adairin Viserak Systems had enjoyed a near century long golden age until the Oya Fleet led by Goratta had pierced right through Viserak space and glassed planet Kippedea as a show of force, AVS premaris: Bororlav Pauergrowt surrendered to them, though non-Adairin Viserak worlds resisted they were defeated by 2602.
Fall of Shrine
After the Allied forces were defeated upon their return to the Sapphirian sector.. Spitter Taigo and his remaining forces pulled returned to Shrine as Matt Tygore retreated to Kandlia. Spitter Taigo upon returning to Shrine found destruction and chaos all across the world fighting through occupying Oya forces, Taigo and his forces stumbled upon the Shrinen Star Beacon , Taigo remembered that with the right frequency, he could alter the beacon to teleport Natogytts toBorelus , after rescuing millions of Shrinen civilians they made the trek to the star beacon (fighting Oya forces along the way) the massive group of Shrinen people arrived on Borelus, However Oya forces were entering Borelus as well, though he damned himself for what he had to do, Spitter Taigo and Blune Bairsen destroyed the Star beacon, while it prevented Oya forces from entering Borelus, it left many millions stranded on Shrine.
In the years during the Oya occupation various survivors who had been stranded joined an anti-Imperial rebel faction known as "The Lost sons"
Return of the Kaiser and the Praetorians
After Kaiser Matt Tygore and Kal: Spitter Taigo's joint expedition to the distant Arcturas sector was complete they returned home to find their sectors in a mess, they fought through countless Oya forces losing 97% of their fleet, before being pushed back to planet Kandlios, which had yet to be attacked by Oya forces.
Matt Tygore reawakened the sleeping Draliska who in turned awakened the Draliksan Empire now reformed into the "Draliskan Eternal will" Draliska launched a major surprise wormhole strike on occupied Earth, devastating the Oya forces there and reclaiming Antarctica for Matt Tygore to begin the process to reactivate the dormant Star Beacons, unfortunately he would have to reclaim at least eight other worlds along with the Centerpoint Station to launch any sort of counter attack, the UTSEA-Psion Praetorian-Kandlian alliance held Earth for over two days before being driven out by overwhelming Oya forces.
The Trump Card
Once Planet Shrine was Reconquered in 2614 the USR reorganized and began fighting back as well, unfortunately Spitter Taigo was killed at the battle of Karsanthenlusz on planet Sholalusz in 2615, despite this Sholalusz was eventually reconquered months later in 2616 the UTSEA was restored as was the Centerpoint Allaince, the alliance drove the broken fleets back to the Osian sector just as a anti-slavery civil war began there, they saw the alliance as liberators and by 2619 Holy Osia was flash frozen by the more powerful Star beacon-Frost Core attack.
As the leaders conclave died out, Kaiser Matt Tygore appointed puppet rulers owned by the UTSEA to take their place.
A cold war however began as forces from three sides began planning to undermine eachother, the UTSEA-USR-TEC-Kandlian Centerpoint Alliance, against the Viserak Transectorial Union who was also against the Federation of Tydoran Systems.