: Why the Didact should have known that the Chief was carrying a nuke:
: Luminaries.
: They're these nifty little sensors that can locate humans and discern an
: advanced AI from all the other electronics on Harvest, and they can do
: this from across a solar system.
: And these are the inferior Covenant-built copies.

: Why the Didact is an idiot for monologuing when the Chief got close:
: Sigh.
: Ok, fine, so I only watched that cutscene once. Whether the Chief was
: sprinting, walking, or breakdancing toward the Didact, the fact remains
: that he was carrying a nuke the whole way. Didact's reaction is not
: "Get that thing away from the Composer", but "Hold the
: Chief up and launch into yet another cliched monologue". Don't get me
: wrong, a good villainous monologue can be truly a thing to behold. When
: it's not... well, it can make the villain look like an idiot. Especially
: when he forgets some very basic precautions.

: Maxim #8 : Mockery and derision have their place. Usually, it's on the far
: side of the airlock.

oh, those
I think you're more or less right, except I don't think the Didact knew Cortana was still in the system, or if he did that he didn't think she was any threat at all. He presumably knew he'd be able to take out the Chief easily (as he almost did), I don't think anyone else had a shot at him, and the Composer was already set up and running, so why wouldn't he think he had an opportunity to talk?

: Just out of curiosity, how long's it been since you played the last level of
: Halo 3?

: Notice how some areas took longer to self-destruct than others? Or how there
: were entire safe zones?

Are you talking about in the Halo 3 end run? In that I'd say the first thing is a gameplay consideration and I'm not aware of any safe zones.

: Some areas will be be impossible for the Didact to drop out simply because
: they're integral to the structure or function of Requiem. That's your
: destination.

I don't think the floor in some random tower would be vitally important to Requiem-- and even if it was, what does he care, he's leaving.

: Even the Chief had to run when the Covenant started glassing.
: And hey, bigger guns would have been a welcome change from fighting
: Prometheans and pushing buttons.

What is it that you think we would've been doing instead? (another quick-time event maybe?)

: Fire control.
: My theory is that the Librarian's modifications changed the Chief enough that
: the Composer didn't recognize him as Human. While the scanning process
: itself was hazardous to human health, the Chief was spared from the full
: deconstruction.

: I prefer this theory because the Composer disintegrated human flesh, bone,
: and even the clothes those scientists were wearing. "Genetic
: modifications" making someone immune to that makes about as much
: sense to me as an MRI making someone immune to bullets.

That sounds like a good theory... why did you ask how the immunity works, then?