I know people are going to come in here and go “YES! 343i lied to us! I feel cheated! ARRRRRRG!” But let’s really take a look at this. Remember when 343 Guilty Spark exploded after taking multiple hits to the face with a Spartan Laser and then he showed up in Halo: Primordium still alive? People had wondered how the heck Guilty Spark could have survived, not only exploding from Spartan Laser fire, but also the destruction of the Halo. Is Guilty Spark truly still alive? The answer is yes… and no.
343 Guilty Spark was a split personality which formed when Chakas had parts of his mind locked up as part of his compartmentalization. When Guilty Spark exploded on Installation 04B, he died and the mind of Chakas returned as the dominant mind. So while the shell and primary mind of Chakas did in fact survive the carnage, the split personality that was Guilty Spark died that day.
How exactly does this connect to Cortana? Well it’s simple really, Cortana has gone through a similar death, except she did the opposite. Instead of a fragment splitting off and dying, her core mind is what died while the split fragment survived. This means that 343i wasn’t lying when they said she died, because the Cortana we knew from Halo: CE to Halo 4 did in fact die. I know it’s a technicality, but it’s still true. This fragment acts like Cortana and probably thinks of itself as Cortana, but it’s not her. We’ve seen this before when she split a fragment of herself off in Halo: First Strike.
Halo: First Strike (Definitive Edition)
Chapter 36, Page 399
“I’ve reviewed your mission logs. Maybe it was the additional copying that caused its breakdown, but that copy did have some of my core personality programming as well. I just hope it’s not a sign of… some other instability.”
This is a clear indication that fragments of Cortana can keep a piece of her core personality, which means that if the real Cortana died, a duplicate could potentially believe she was the real Cortana. I believe this is what happened in Halo 4. Cortana died when she gave everything she had to get Chief off the Mantle’s Approach, but those core fragments which remained were pulled into slipspace and they pieced themselves back together believing they were Cortana.
That’s why this Cortana believes all the things the Gravemind told her, like her being an expendable piece of hardware. The real Cortana told him he was wrong and that she would die for a human, which she did in Halo 4, but not the Halo 5 Cortana. Instead she’s going to impose her own order on the galaxy. The Ur-Didact was going to do the same thing because he was also corrupted by the Gravemind. That’s all this is.
