CODEXes :

• Leviathans :

1 billion years ago, the galaxy was ruled by the oldest mortal race in the Universe. The Leviathans (from Mass Effect) were the size of Starships, and were originally ocean dwelling beings, with an appearance similar to Earth's giant squids, but much shorter tentacles.

They have the technological means to fly, and even survive in space, with no need of a starship.

The Leviathans viewed themselves as the ultimate lifeform, with superior telepathic powers. They would invade the minds of all other species they encountered, and make them want to serve them. However the creatures they enslaved still retained their personalities and much of their independence.

These "Lower" lifeforms were viewed largely by the Leviathans as pets. Something to spoil and pamper, however they still were expected to assist their masters with various task the bulky body of a Leviathan was unsuited for.

They viewed these "Lower lifeforms" much as how humans view "service animals". Complete with the mindset that Sapient life was inferior to themselves, and therefore needed the guidance and protection of the Leviathans.

The Leviathans once had a massive Empire, stretching across the whole of existence. However they wanted easier travel, and so merged the existing, 1000 galaxies, into one massive galaxy

Reorganizing all planets, to follow the same length of days and years. With an hour consisting of 100 minutes. Then a day lasting 42 hours, spread equally between day and night. Followed by 10 days, in a week. Then 5 weeks in a month. And 600 days in a year.

All the planets, capable of evolving life (not necessarily ones with life, but at least capable of evolving it) where made to follow this rotation and orbit. Then placed into Quadrants of similar evolutionary capability.

With each of these organized into quadrants, orbiting around their own Ring like space station (Based on the "Halo" franchise). These systems orbit the rings, while the Rings orbit a massive Citadel, at the center of the Galaxy.

The Citadel was made from a trillion black rocks, worlds incapable of ever supporting life, and given Earth Norm gravity, in artificial environments throughout the inside of the Station.

While there are shops and apartments, all throughout the levels of the Citadel's Arms, the ring at the center, was designed for the operations of government.

Such as: the embassies, a Senate chamber for the "lower species", and various other government offices, including Security. It also had Academies, to train children with atypical manifestations of magic... AKA "Superpowers", or "Classes".

While the inner Ring of the Citadel was used for docking space ships. There was even an entire floor dedicated to amusement parks, as The Leviathans, wanted to make the aliens they indoctrinated comfortable.

Throughout the billions of floors of the Halo Rings, and even within the Citadel itself, were several Artificial environments, to grow food and provide water. There are various machines meant to purify and maintain the Citadel's water supply. As well as machines to artificially create water, air, and nutrient rich soil.

While the gravity outside the Citadel was strong, inside was Earth Norm, regardless of mass. This is due to the Leviathans having an advanced understanding of magic and science. They were able to greatly alter the mass of an object, to be comfortable regardless of size. Although the gravity is powerful enough to keep all the galaxies in orbit. It does not affect ships with their own artificial gravity.

• Language:

The Galactic Standard language for the Citadel races is a mix of English and Japanese (but all written in the American style and spoken with American grammar). This is because that is the native language of the Leviathans. However thousands of other languages do exist throughout the Universe. Having evolved from their language.

• Reapers:

The Leviathans once used their natural indoctrination magic to enslave the galaxies, but realized that their servants kept building Synthetic Lifeforms. Which would inevitably turn on the "lesser beings". So the Leviathans built an AI of their own. This was meant to study the phenomenon, and discover a solution.

The solution the program created, was to build an army of Starships, made out of the essence of the sentient lifeforms. Entire civilizations would be converted into new self aware ships, AKA Reapers.

They left various technologies behind, to guide future species to develop the way they wanted them to, then drove the Leviathans into hiding.

It is said, the Reapers actually created the Mega Galaxy. During the first paradoxical war, at the beginning of the universe. However, most respectable scholars do not believe this "Time War" ever happened... despite Legends and myths about such an event existing in every culture.

• Citadel :

1 Billion Years Later, during the Reapers last "Harvest" cycle.

The Citadel is an ancient deep-space station, the size of a trillion worlds. Made of a "Ring", and 5 "arms" called "Wards".

The Citadel has two complex modes of travel. With public transportation consisting of faster then light turbo-lifts. And then tunnels for more personalized hover vehicles.

The Embassies are held within the Presidium, the Citadel's inner ring. With the outer shell being where ships park, with the crew having to go through Citadel Security, or "C-Sec", to legally progress into the station itself.

The Citadel Tower, in the center of the Presidium, holds the Citadel Council chambers. Council affairs often have far-reaching effects on the rest of the galactic community. Their various decks, have been built into cities, populated by near a trillion inhabitants, from races across the galaxy.

The Citadel is virtually indestructible. If attacked, the station can close its arms to form a solid, impregnable shell. For as long as the station has existed, an enigmatic race called the keepers has maintained it.

The Citadel was formerly believed to be constructed by an ancient race called the Protheans. But now it is known, to have been constructed by a race of Sapient spaceships, called "The Reapers". Which were defeated over 300 years ago. And are now being lead by the program "Cortana", the former AI Assistant to the Spectre "John Spartan 117", AKA The Master Chief". As The Spartan uploaded the AI as the new Command Mode, to take control over the Reapers.

Numerous species now call the Citadel home. With it serving as the political, cultural, and financial capital of the largest galactic community, the Citadel. Other governments have settled their capital on stations, in orbit around the Citadel.

With most species, having an embassy on the Citadel, in addition to being part of another intergalactic Government.

This is only possible, as The Citadel has pledged to stay neutral, between Interplanetary conflicts. With their military only stepping in for Galactic threats, and as domestic police. While the Citadel Council often acts as a neutral third party, during diplomatic discussions or disputes, to promote peace.

• Citadel Council :

The Council is an executive committee composed of representatives from the 42 most influential species of the universe.

Though they have no official power over the independent governments of other species, the Council's decisions carry great weight throughout the galaxy. No single Council race is strong enough to defy the others, and all have a vested interest in compromise and cooperation.

Any species granted an embassy on the Citadel is considered an associate member, bound by the accords of the Citadel Conventions. Associate members may bring issues to the attention of the Council, though they have no input on the decision.

• Prime Directive :

As part of an intergalactic treatie, for all Citadel races. Only planets capable of traveling faster then light, have colonized other worlds, or are capable of sending a real time transmission outside their solar system, are permitted to be contacted.

There is to be no trading or interaction with these civilizations, outside global disasters. With no interference in how their world develops.

Even with space fairing races, their culture must be respected, so long as it doesn't directly contradict Citadel Law.

• Citadel Space:

Citadel Space is an unofficial term referring to any region of space controlled by a species that acknowledges the authority of the Citadel Council. At first glance, it appears this territory encompasses most of the universe. In reality, approximately 42% of the stars have been explored.

With the help of "Reaper" tech. Each Ship is outfitted with it's own personal "Mass Warp Drive", which allows them decrees their mass, while bending space, allowing them to travel several million times faster then light.

With this, it's possible to get from one side of the universe, to the other, in 42 years. Which is what allowed them to explore nearly half of the universe.