None of you guys are even close to the plot of Halo 5. Come on, show some creativity. The death of Cortana, the ending, and the Spartan Ops spoilers all points to the plot. First off, Cortana is gone. If she does come back, she will only do it at the end of Halo 6, and she won't be back for good. I highly doubt she is coming back.
Ok, now for the plot. So obvious. With all the Spartans he grew up with long gone, Keyes long gone, weariness from a lifetime of war and saving humanity, Master Chief is getting old and feels it. Now, with his last close friend, Cortana gone, he looks in the mirror and for the first time, stares at his own mortality. While everyone around him still looks at him as a God, he starts to questions who he is and his past. Everyone he knew is dead, but one. The only person from his past still alive is the only one who can help him understand where he came from, Dr Halsley. Halo 5 will be the search for the tech cache alluded in the Spartan ops and saving Dr Halsely. Halo 5 will be very much about Master Chief and Halsley and him coming to terms with the original spartan development. It'll delve into the kidnapping of children for that Spartan program. This was a constant topic in the cutscenes from Spartan Ops. Master Chief will struggle in Halo 5 from both the enemy and his past. This will likely come at the worst moment against the worst threat that humanity ever faced, and he will lose as Halo 5 ends.
Halo 6 will be his rise from the depths to sacrifice everything to once again save humanity. Both Halo. 5 and 6 will be heroic, but it will mostly be a personal battle for MC. It will also bring the players to terms with what Spartans really were. One part super soldier. One part kidnapped child, put under extreme training, sent out to war , only to lose friends and loved ones, never getting a chance to live a human life. It'll likely be the best two Halo yet. Master Chief will leave the world and humanity for good. It'll be fitting end for a man who never got a chance at being anything but a weapon of war and would not know how to fit in at this point and yet sacrificed everything for its survival.
