Please elaborate. Humanity was chosen to hold the Mantle of Responsibility. Didact stole it. Repopulated the universe as he saw fit. Shortened humanity lifespan. Humans find Flood. Confusion War between to the two happens. Humans win. Librarian with the composer created a machine that would digitize the forerunner race to save them from the flood humans brought. It was corrupted. The consciousnesses already converted were left fragmented and in pain. Didact decided to use the corrupted Forerunners as his army. He converts entire civilizations into his minions. Librarian put herself into the machine and traps Didact. All life is wiped out by the firing of the Halo array. John finds the Librarian. She sees that a prefect harmony of organic and machine has been achieved with John and his ancilla. Finally seeing the missing pieces from their failed attempt at digitization. She uses the composers machine on John and Cortana evolving them centuries forward. This solidifies what the Librarian has always known. Humanity is the chosen keepers to The Mantle of Responsibility. Cortana is now a living digital lifeform. No longer governed by numbers in code. She is made real. As such has a mid-life crisis of ethics and identity. Becomes dangerous. John must save her....as always. My Halo Lore is strong bub. You can have anybody write a million books about a game after the game has been made and slap Microsoft approved on it. But until it is actually in the game. It's not officially apart of said game. Just fan-fiction with advertisements.

You said at the beginning that all races in the universe were created by the forerunners. The precursers created all life including the forerunners. And they chose the Humans to uphold the mantle of responsibility. Forerunners then acted like spoilt children and fought a war that left the precursors wiped put save for one. This precursor was later discovered by the didact and later became the flood itself. Oh and the didact had used the composer on a lot of humans which is why that machine wasn't ethically agreeable to the forerunners. The forerunners then took as many species as they could to somewhere safe while they detonated the halo rings. And then they returned and repopulated the universe. And the didact was sent insane due to the talk he had with the last precursor and the fact that there were two didacts and one didacts family didn't love him and the other felt that everyone was going to betray him. Just tryna point out that that bit was off.

Yeah but once the Didact's actions killed everyone with the firing of the Halo array.....everything with an organic body died. All life today was repopulated by Forerunner technology. Even The Flood. So that is why I said they created all the races. Cause they did. I also think The Precursors are The Flood....or the other way around. See they did they same thing to themselves as the Forerunners. Only instead of digital, they turned themselves into dust. I believe The Flood is the evolved so called "dust." Explains the collective consciousness Gravemind as well.