Halo 3 Campaign Question - Cortana Visions

So of all the Halo games, and all my time playing Halos, I’ve definitely played Halo 3 the most. I know the multiplayer, and the single player like the back of my hand. Or, at least I think I do. Anyway, if you’ve played Halo 3, you know that at some moments during Campaign levels, a distorted Cortana will take over your view and say some cryptic and creepy stuff, or talk about the history of you (Master Chief). So I know that she does this, but… I’ve never asked why?

Why does Cortana pop up on the screen like that? Is she trying to contact Chief from High Charity where the Gravemind and her are? Is HE having the flashbacks, and remembering her, did Cortana inject, or download part of herself into Chief and it’s affecting him, or was it simply put in their by Bungie to help tell the story, and drive a narrative?

I thought the later. Back to when I was saying that I like to think of myself as a Halo 3 expert, and expert on Halo in general. (Cocky -Yoink-.) Every time it happens in the story, I ignored it, and just thought it was that last reason. But I recently just played the level Sierra 117 again, and the first time Chief get’s a vision, two marines turned around and said, “Chief, are you okay?” “Your vitals just read KIA.” At that moment, It made me think, okay there is a reason for it. Whatever it is, but what, and how is it affecting Chief?

This is never explained somehow in the game, so does someone know why it happens? I’ve played the games I’ve read the books, but I never understood why it happened, and now I feel like there is a reason it does. Thanks.

Hmm… I do not have an answer… but it is interesting… I just beat Halo 3 the other day, I was trying to figure it out… but idk

Yeah, I just beat it all again in a playlist while achievement hunting, and I still don’t know.

I think it’s because Chief and Cortana are strangely linked together. It seems that Chief’s mind becomes unstable at the thought of Cortana being in danger. I say this because this behavior wasn’t seen in Halo: CE when Chief was in the swamp and the library of Installation 04, alone and without Cortana. Only when Cortana was in jeopardy did Chief start acting this way, the first example being the visions in Halo 3. The second example would be in Halo 4 (spoilers ahead). When the terminal Cortana was inserted into got destroyed, Chief started hearing Cortana’s voice. Perhaps it’s because Chief lost so much that the idea of losing yet another companion is consuming his mind. Either that or it’s Chief’s mind hallucinating Cortana’s presence.

It’s most probably a mental thing.