I got this idea from the Dawning Event- you know hidden present with the sparrow inside- that got me thinking 'what if the Concordat made a return in Destiny 2'. Not a bad idea, I might say. And this has my version of the Destiny 1 storyline.
For three years, one Guardian- a Titan- and his Fireteam- a Hunter and a Warlock- have made more of a difference than any other Guardian in history. Their names were Excalibur (the Human Titan and leader of the team), Raya (the Awoken Hunter and scout), and Sov-8 (the Exo Warlock of and hacker expert) together they formed Fireteam Olympus. Excalibur was resurrected almost four years ago, and has done much in that time. He Became the Kell of four Fallen Houses, the House of Winter (by killing Draskis on Venus), House of Exile (by helping them fight the Hive on the Moon), House of Wolves (by helping find safe refuge in the Last City), and the House of Devils (by killing Akiss, the Archon Prime in the Cosmodrome, on Earth). He even forged an alliance with the Cabal Empire behind and join the Guardians. Raya was first resurrected just before the Battle of the Twilight Gap and became Excalibur's girlfriend after the destruction of the Black Gardens Heart. She was an expert sniper and scout. And Sov-8 has been around since the Battle of Six Fronts, and was a shilled decoder- he even cracked the Sleeper Simulent and Outbreak Prime codes. He was also the one who killed Crota and Oryx in both raids.
They met on Venus, when the Exo Stranger called them all to the Ishtar Academy. And since then they were inseparable. Excalibur was different from almost all Guardians, he actually studied the Darkness and learned how to make weapons from it (like the Touch of Malice and the Necromanism), he also studied his enemy.
When Fireteam Olympus was on the quest to forge their own Gjallahorns (during the mission "Honor the Past" sorry if I got the name wrong), they found a Redjack frame- Shaxx's personal battalion of combat frames- in a cage, at Bannerfall. Once they freed Dalthia- 99-40, got the data and components to build their launchers, they were attacked by two Hawks worth of combat frames and a Veteran Titan, claiming they've went rogue. Hearing this they headed back to the Iron Temple, where Tyra Karn and Sov decripted the data hidden inside Dalthia, what they found shocked them. The Speaker had committed unholy acts of murder and Genocide against Outsiders, for not submitting to his authority (Outsiders were people who didn't answer to the Consenses, Factions, or the Speaker). There are also records that date back to before the City Age, in the end they came to a conclusion- the Speaker is a Warlord. Centuries ago the Iron Lords fought the Risen Warlords, and it is revealed that their "leader" was one of them (makes sense when you think about it). The people had to know the truth, so they broke into the City News Center (CNC) and broadcast the files across the whole solar system.
It was pure chaos, Dead Orbit declared itself independent of the Consenses, the alliances with the Cabal and the Awoken were ended, the Vanguard took as many civilians as they could and scattered across the System, and the Iron Revolution had begun. A war between the New Iron Lords and the Speaker, winner will determine the fate of humanity, if not the fate of Sol (the solar system).
The Iron Lords had an advantage the Speaker didn't not have: allies. Lord Shaxx and many other Guardians that fled the City, joined their revolution, not to mention Excalibur ruled over most of the Eliskni, by combining the four houses in one massive house (the House of Dusk), then there was Cult of Osiris and the Sunbreaker Titan Order- which Excalibur secretly joined- who been against the Speaker for as long as anyone could remember. The war was on.
The Last City was turned into a fortress, the Speaker had the loyalty of Zavala and some Guardians- believing that humanity needed the Speaker. THe Speaker also had another weapon in his arsenal- SIVA- the City foundries managed to find a way to control it. The citizens were being held against their will and anyone who resisted were killed. The Iron Lords had completed multiple successful operations against against the Speaker the past year, with little to no defeats. It was only a matter of time before they would attack the City and bring the Speaker to justice.