The didact falls through the slipspace anomoly and takes all the inhabitants of new pheonix that were destroyed by the composer with him to create a new army of protheans, he also takes cortana, or what is left of her, and creates a prothean out of her.
Neo/Prothean-Cortana leads army against humanity.
Chief and Arby destroy her army but save her, and along with halsey's help, cortana finds a way to make a more human body based off prothean tech. She, Chief, and Arbiter destroy didact once and for all.
Human-Cortana and Chief get married at the end of halo 6.
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