Probably gonna need further refining, and I'm likely to find it complete crap when I wake up, but screw it I'm tired

Name of nation: The Collective
Species: [url=http://starempiresreboot.wikia.com/wiki/Triarii]Triarii[/url
[url=http://starempiresreboot.wikia.com/wiki/Saeva_Simius]Hara-Ka[/url]
[url=http://starempiresreboot.wikia.com/wiki/Umbrae_Populus]Ziatri[/url]
[url=http://starempiresreboot.wikia.com/wiki/Corruptelae_Insectum]Corruptelae Insectum[/url]
[url=http://starempiresreboot.wikia.com/wiki/Selkath]Selkath[/url]
[url=http://starempiresreboot.wikia.com/wiki/Honoratissimus_Aviarius]Aru'Shumi[/url]
[url=http://starempiresreboot.wikia.com/wiki/Lance_Humans]Human (Lance Genus)[/url]
Small number of Draconians
Various non-sentient species
Previously: Asari, Batarian, Turian (Now Extinct)
History:: The Triarii are a highly intelligent species. They managed a rather quick evolution from hunter-gather to space faring species. With their doctrine built solely around the greater good, war was almost completely unheard of, soldiers being bogeymen with which to threaten children. The greatest war in Early Triarian History was the War of Tenebris, or War of the dark times, which lasted a mere one earth day and left only 102 dead. Ethics were left in the dirt

Eager too start, the Triarii spread throughout the stars. They dreamed of meeting other species that could trade knowledge with them and indulge in creating an intelligent, peaceful alliance with these species. But this was not to be. The colony of Chron was taken from them by another empire, The Xorg. A mass genocide ensured no Triarii survived the attack on the Colony. A huge blow, given the slow reproduction rate the Triarii usually indulge in. Nonetheless, the Triarii attempted peaceful negotiations. The colony of Stret fell and the Triarii changed their tune. They build a relatively large fleet of powerful battleships (During the construction the colonies of Zils and Poi were also exterminated). The Triarii took the fight to their enemy. In the conflict that followed resulted in the victory of the Triarii... but it came at a huge cost. Many Triarii had lost their lives and it took 50 cycles before even a fraction of that population was restored.

Unable to cope with the thought of such losses again, the Triarii constructed a huge and effective millitary fleet. Their advanced technology was incorperated into each one, including their new weaponry. 
After two years of the Great War, the Draconians attacked and destroyed the Aetherii Remenant as it seemed the Triarian Collective were about to enter the war and the Aetherii Remenant posed the problem that the Triarian Collective might get even more advanced technology. The Triarian Collective, filled with rage, sent a message to the Draconian Empire
"This is not war, this is pest control! You are superior in one respect, you are better at dying!"
The Collective quickly joined the fray, mobolising their entire fleets. Asteroids filled with Corruptelae Insectum were flung at Draconian Space, some managing to slip past Draconian defences and infest entire worlds, killing indiscriminately. As soon as the Triarian Collective were able to lower the defence grid of a planet, Energy Projectors were used to burn the planet to glass. Any captive Draconians were quite literally used for parts, being used to build Synths. Civilians made up the bulk of captive Draconians, men, women and children.
After the Destruction of the Draconian Empire, genocide by the Triarian Collective ensured that the Draconian race was sent into extinction and any surviving Draconians are hunted down by Triarian Ghost and Spectre forces, and any Draconian found was sentenced and summarily executed. Spectre and Ghost became the nightmares of Draconians, capture often involving undue force that would cause extreme pain. Often, execution would be performed through the most brutal means the Collective could find. Females were restrained against rocks in hive worlds and infected by Corruptelae Insectum and Males would have their minds destroyed through Psionics and their bodies then taken to be genetically repurposed. The Children were killed and turned into food to be fed to the troops. If the Draconians were lucky, they would be simply shot by their captors, but this was much rarer than the more elaborate former punishments
During the Universal War, the Collective inadvertantly collided the Primary Universe with the Secondary Universe as a result of the usage of a new piece of technology in an attempt to end the Universal War. This result in many storms erupting across the universe which have completely destroyed an unknown number of sentient species. In addition, this rendered the traditional means of Collective inter-galactic travel completely impossible, and standard travel across the galaxies implausible due to the dangers arising from 'tears', holes in space time where the Primary and Secondary universes have collided. Another effect, coupled with the effects of the Universal War, was the near complete destruction of most extra-galactic holdings across the universe. The storms disolved quickly in the milky way, but not before devastating entire planets and wiping out many different lifeforms across the galaxy. The effects of this collision are estimated to last a further 500,000 years These tears weakened not just the barrier between the primary and secondary universes, but other universes as well, and this allowed for the arrival of more extra universal entities
In short, the Collective caused a universal apocalypse in their attempts to end another universal apocalypse.
As a result of this, the Collective could not reach it's extra-Galactic holdings, and as such they fell one by one as their defences failed and no reinforcements came from other galaxies. They were picked off one by one. The Collective was locked in a losing battle for many, many years. Tens of millennia passed before the tide finally turned. Armed with a refinement of the piece of technology that caused the Universal Cataclysm Disaster, finally perfected after many Triarian Lifetimes of work (Thousands of years) they were able to destroy the extra-universal threat and finally 'reclaim' their own universe. And what was left of the Collective, drastically reduced in size, man power etcetera, stood upon an island of corpses in a sea of blood. Although brutally beaten, they had held.
For the first time in living memory the section 'The Greater Good Prevails' was played. But there was no celebration. Everywhere one looked they would see death, they would see decay. Everyone had lost multiple family members and many had known only war. As such it was branded the single most horrific war in Collective History. After the war, a recording of the traditional Umbrae Populus song, Dium'zul, became the number one played audio track within the Collective and remained so for many cycles.
"Dweade a doi e'tol
Mi dium ond zia.

Diwethaf'wym soli'un nod ywr
url'kise gaefa troi at card iar

Dweade a doi e'tol
No'l Card'aid bachk er soli'on rro nod ywr
Mi dium ond zai 
Hurl'wym er pam gollais aid"
With the destruction of the homeworlds of many of their Extra-Galactic client races, the Collective was forced to reallocate former Habitat worlds for cultural reasons, and the massive terraforming attempts to make the planets seem closest to home took massive amounts of the few remaining resources. Approximately one point two cycles after the end of the Universal War and the elimination of (known) Extra-universal life from Universe 1, the Triarian Collective dropped the former part of it's title, declaring it's self merely 'The Collective'.
Having focused primarily inwards and little on locating new species as they once did, they have no idea that the other species they previously knew of have survived, and many don't even know they exist... such is what happens when you have gone without any real contact for 50,000 years. The Collective forces self-proclaimed themselves the 'Guardians' or the 'Sentinels', and the Collective it's self prides it's self on being one of the oldest known continous bodies in the Universe... as it turns out, having survived the Universal War inflated their planet sized ego to the size of a star, paticularly with the Triarii.