A/N: Putting this at the top, to make sure everyone will know exactly what this is. This is going to be purely Codex entries for "An Empire Reborn." I didn't want to have info-dumps in the story itself, but it's impossible to naturally work in all the background detail and world-building going on in this story.
For the first entries here, I'll be focusing on the biggest questions people might have from the story. Please tell me in reviews exactly what you are most confused or curious about, and I'll add entries here to address those subjects. That said, some things I will not be able to get in here, either because they haven't actually been revealed in the story yet, or because I simply want to leave them a mystery.
Oh, and I will be using somewhat edited versions (partly rewriting in my own words, but mostly changing or adding things to make them fit the updated lore of this story) of the Destinypedia and Mass Effect Wiki pages for a number of these. If you'd like to read the full unedited entries, you can find them there.
Also, THIS FIRST ENTRY WILL CONTAIN SPOILERS FOR THE LEAKED BLACK ARMORY CUTSCENE!
Humanity and The Sol Territory
During the 21st Century, humanity made first contact with the mysterious entity that would later come to be known as the Traveler, the arrival of which ushered in a centuries-long Golden Age that saw humans colonize the newly remade worlds of Sol including Mercury, Venus, Mars, and even the moons of Jupiter and Saturn.
But this Golden Age would not last. Unbeknownst to humanity, the Traveler had an ancient enemy; a powerful Darkness that precipitated the Collapse and nearly wiped out mankind, if not for the intervention of the Traveler who sacrificed itself to push back the assailing Darkness. And with its dying breath, the Traveler created Ghosts to seek out those worthy to carry on its task.
In the dark decades after the Collapse, Humans, Exos, and Awoken found the Traveler where it made its final stand and built the City—the last bastion of mankind—beneath its shadow. And from an age of chaos and death began the City Age.
Though its tenuous peace lasted for the better part of a hundred years, the City Age would ultimately come to a shattering end in the wake of the devastating Cabal invasion; with the heroic deeds of The Guardian bringing an end to the Red Legion's siege and marking the dawn of a new Golden Age.
The speaker acts as the head of the Consensus. The Warlock who was the original liaison to Calus - and who led all three teams to venture onto the Leviathan - became Calus' Shadow of Shadows and also took up the role of Speaker.
Under Calus' rule, the Vanguard's organizational structure has been left largely intact. It is still run by the three Class Mentors. Zavala remains the Titan Mentor, and still oversees Guardian Combat Operations, for instance. There are, however, some notable changes.
Ikora was offered the position of Director of the IIS (Imperial Intelligence Service) and accepted it. She has integrated her Hidden into said IIS, and implemented new training for existing IIS Operatives. Given the vast scope of her new job, she decided to step down as the Warlock Vanguard, nominating one of her students by the name of Praxidike Meng in her place.
Cayde's replacement to the Hunter Mentorship was, in accordance with his Vanguard Dare, his killer Uldren Sov who had been resurrected as a Guardian after being killed for Cayde's death. Uldren's memories, however, were entirely gone. Seeing this as an opportunity, Emperor Calus gave his Shadow of Shadows the duty of assimilating Uldren into the Vanguard, and becoming Uldren's mentor. The Shadow of Shadows pursued this duty with great enthusiasm, seeing this as a chance to remake Uldren in their own image.
New Monarchy embraced Emperor Calus' rule after being given access to the Leviathan's historical archives. They now serve as his primary advocacy group throughout known space.
Dead Orbit's mission statement never changed. It has always sought to expand humanity beyond the Sol System, making them a multi-solar species. Now it no longer had to convince humanity to expand beyond the Sol System, since the Sol System itself was safe. Nor did it need to find or develop the necessary resources to colonize beyond it. Instead, it was given the mantle of settling humans within the Empire.
It was also given the directive of advancing life-sustaining and prolonging medical technologies, as well as managing the human population's growth, including providing child care programs and incentives for having children. After all, humanity didn't have to worry anymore about limited space and resources, stuck inside the walls of the Last City. Rather, the most pressing concern was low population numbers.
Future War Cult
Seeing the Future War Cult as a potential threat to his rule, and their predictive machine as being too dangerous to be left to anyone else, Calus confiscated all material relating to the machine and ordered the Future War Cult to formally disband. With great reluctance, tempered somewhat by humanity's present and even future prosperity (according to the majority of outcomes already predicted by their machine), Lakshmi-2 agreed.
The FWC members were all offered jobs fitting their expertise. Evangelists were offered teaching roles. Technicians were offered jobs at the Department of Municipal Planning, to work on developing city planning and management AI. Lakshmi-2 was offered the role of Director of the Department of Municipal Planning but refused, opting instead to become Head of Territorial Planning for the new Sol Consensus.
The Consensus was the governing council of the Last City. It is composed of five members: one representative each from Dead Orbit, New Monarchy, the Future War Cult, and the Vanguard, plus the Speaker. The Consensus changed its name to the Sol Consensus and had its role expanded to encompass the entirety of what was now called the Sol Territory, formerly referred to as the Local Bubble.