: What reason does Cortana have to subscribe to the ideology of the Mantle in
: the first place, though? It's not some indisputable, universal goal
: civilizations must work towards, it's a Forerunner/Precursor religion that
: conveniently justifies the idea of one species or group ruling over
: others.

: I never really saw Cortana as the religious type. More like the kind who
: would dismiss the whole concept of the Mantle with a snarky witticism.

I think it's a pretty natural impulse, for good reasons or ill, for the powerful to view stewardship as necessary and proper, and I can see Cortana, once she has the means, to certainly be interested in using them. I mean Cortana is really the facilitator of the survival of the human race—Chief did the brute killing and the point A to point B stuff, but it was Cortana who hacked, detonated, and disrupted the enemy. If everyone would just do as she says, really, everyone would be better off. It's a pretty intoxicating attitude, and plenty of smart people through history have fallen for it (and it's not even that she's particularly wrong, either, it's just the question of whether you think the costs are worth it.)

You don't need religion or a higher power to believe that you have a cosmic mandate. Just as some of the most rapid religious people are the guys who profess to believe in no religion. It's the same impulses, different outlets.

I think her attitude is also colored by her rampancy and near-death experience. She reacts quite nastily to Halsey's invocation in this game, and I don't think that's "OMG 343 hates Halsey" bashing; I think it speaks to confronting her mortality and the fact that she was a sentient being created, with everyone fully knowing she was doomed from the start to a short existence and perfectly fine with that. Even Halsey's own journal seems focused on AI metastability more as theory and advancing tech than any concern about saving her AIs.

Part of the problem with understanding just what Cortana went through though is we only find her after her ordeal and her "salvation" through the Domain, and not really knowing what she found within the Domain beyond her own immortality. It's entirely possible this isn't the Cortana we thought we knew, as some have suggested, but I think it's tidier conceptually and narratively that it is. It sucks when people you thought you knew and used to agree with turn against you (and they in turn view you as turning against them) but it's pretty common when you're playing with big stakes.