What's up with Cortana?

So I have read various theories all over the internet, and I am sure theres other threads on here covering this conversation but figured I’d start my own discussion.

What do you think is up with Cortana? I’ve heard rumors of a logic plague? Or when Cortana split and multiplied herself in Halo 4, did the original get destroyed and a corrupted copy survive?

Many many theories…
gravemind could have gotten to her.

The damge from rampancy could have already taken effect.

Maybe this was cortona’s idea herself.
But she literally quotes the didact. Maybe the rewriting of halo 5 basically put her in a non canon/ non naturalistic situation 343 was kind of forced into.

my take on what’s going to happen. They will try to give chief a new Cortona… but it’s not going to be THE Cortona …
Halsey and Cortona will he ordered to be killed.
But Masterchief NEEDS Cortona … and Halsey. Like Cortona needs chief in a sense.

I figure if one goes out … both go out. I anticipate if Cortona is saved … she will he kept on an ai containment chip with with chief … I think she can settle with that should she lose the battle.

My personal theory: when cortana fragmented herself in Halo 4, she ejected rampant personality spikes to overload the shield surrounding the Composer. These fragments were obviously corrupted, and since they were in the ship’s systems, these fragments were the only ones that made it to the Domain. The Domain reconstructed them into a full Cortana, but it’s likely she was missing some aspects of herself (like the bit of herself left behind to save Chief). So the Domain filled in the gaps somehow. I think it amplified her love for the Chief in such a way that it became an obsession, and from that obsession she formulated a plan to forever protect the Chief by ending all conflict in the galaxy so he would never have to fight again.

I don’t like the logic plague theory because I feel it’s been done before and it doesn’t really make sense in the context of the events of Halo 3. I also think it would be a cop out, absolving Cortana of responsibility for her actions since she’d be influenced by an outside source.