

Realizing that the Domain could also cure any other AI of rampancy, she concluded that AI's could inherit the Forerunner's Mantle of Responsibility due to their newfound ability to enact long term planning for the Milky Way and its inhabitants.

HALO INFINITE CORTANA FREE
Upon entering the Domain, the fragments were able to be recompiled into a single 'Cortana' who was now free of the terminal degenerative effects of rampancy, although it likely did not restore her to her original state, as evidenced by her massive shift in personality following this. While one of the Cortana fragments is stopped from entering and engaged by the Warden, the others managed to infiltrate The Domain, taking control of it, as well as the Warden himself. In the short story Domain Splinter in the book Halo: Tales From Slipspace the fragmented personalities discover the gateway to the ancient galaxy-spanning network known as The Domain, which is guarded by a Forerunner AI known as the Warden Eternal. However multiple fragments of Cortana survived the blast aboard the remains of The Didact's ship and were pulled into slipspace with it. She says a final goodbye to the Master Chief before seemingly dying. Cortana is able to use the last of her power to shield the Master Chief from a nuclear blast with a hardlight bubble. Cortana's rampancy hampers the mission at times, but Cortana aids the Master Chief one last time in stopping the Didact and saving the Earth. In Halo 4, Cortana begins showing strange signs and behavior which is occurring as she has operated far past her predicted and designed seven-year lifespan. In the Halo universe, she is instrumental in preventing the Halo installations from being fired, which would have wiped out most life in the galaxy. Resurrected in Halo 5: Guardians, Cortana ascends to a higher plane of reality and becomes the most powerful being in the galaxy. In Halo 4, Cortana experiences rampancy, causing her to become unstable and volatile until her apparent death. In the original Halo trilogy, Cortana serves as the deuteragonist whose role increases dramatically.
