By the power of truth, I, while living, have conquered the universe.
Posted by: StealthSlasher2
Posted by: ajw34307
Posted by: Alfdog
Bornstellar Didact was the Halo 4 Didact
Nope. It's the Ur-Didact in Halo 4, the Ur-Didact's features became hideous in the Terminals where he attempts to mutate himself into a form that is invulnerable to Flood infection but it fails, this happens after his brevet-mutation on Bornstellar.
Bornstellar-Didact is the one who fires the Rings, the Terminals make it abundantly clear that it's the Ur-Didact in Halo 4 and common sense essentially dictates it's him from his dialogue in the game.
What timestamps the event seen in that Halo 4 terminal after Bornstellar's brevet-mutation?
The fact that he turns to the Composer as his final option, thus being after Mendicant Bias' betrayal. The Bornstellar-Didact spends his time travelling around the galaxy helping the Librarian index races according to Silentium's description:
the Bornstellar Didact, who accompanies the Librarian as she preserves specimens against the dire possibility of Halo extermination.
Silentium also sets up a conflict between the Ur-Didact and the Librarian, which we see come to fruition in Halo 4.
Only the Ur-Didact and the Librarian -- husband and wife pushed into desperate conflict -- hold the keys to a solution.
Librarian's "key" to this solution is humanity, nurturing them to attain the Mantle. The Ur-Didact's "key" is the Composer, using it on humanity to turn them into his Promethean-Knights.
This is therefore set after Bornstellar's brevet mutation, since it's only after the meeting with the Juridicals that this solution seems to be discussed.