We know how a lot of us did not like the story cause it barely fit anything of how it was marketed. It was rushed, not well executed or just plain confusing. So, I will write down how it should have been with detail, but still summarized.
Osiris: The mission stays the same. Everything fine…maybe make it longer so it can have more replay value. And have the fight with the Covenant leader better.
Blue Team: Same thing until the little vision he was given of Cortana and the Guardian. Then at the end when Chief says “Contact with Cortana” and the INFINITY goes “We got another team already on it” it makes Chief actually get mad and go on leave to find out what Cortana was talking about.
Glassed: At first order by Lasky and ONI was to extract Chief. Force if necessary. During the cutscene with Buck and Locke, they talk and stuff as Buck gives his points on leadership back then to Locke but then was shut down as Locke didn’t need to know that stuff… causing conflict between Buck and Locke. When Buck goes “When they find out what we are doing they going to hate us” and Locke goes “You are not the only one here because of him” making Buck think what Locke might plan to do. Then the mission starts. The gameplay and movement can stay the same to the end. AI Sloan stays the same too.
Meridian Station: Really nothing here. Maybe add Buck to tell Locke like “What do you plan to say when we see Chief?” Locke goes “Not much of say, but do.”
Unconfirmed: This one, they hunt Chief down in the caves and face through treacherous fights until they reach Warden Eternal to fight. By then, Warden tells false information as what Chief is doing like “The other human’s passage is given through his support on Cortana’s campaign on Peace”. Warden then attacks Locke’s team and Locke believes Chief just switched through another side with Warden (Which isn’t the case as it is false belief). They beat Warden and go through gates and sees Blue team. Locke says stuff like 'Stand Down! You have committed treason and associated with the enemy Warden Eternal and you will be taken in custody back to the INFINITY" as Chief looks confused, sends team through teleporter and Chief goes “I don’t know what you are talking about, I got a job to do.” and Locke says stuff that pissed Chief… leads to fight… then at the end, Locke pulls magnum to shoot Chief and Buck goes in surprise but Chief already planted the armor lock before Locke could fire. And Chief goes through portal. Locke’s team escapes cave (Id rather ignore the part where Buck almost died. It was kinda unnecessary as it just lead to little humor little on).
Evacuation: Beginning Buck goes “Locke what were you thinking?? That wasn’t the order.” and Vale agrees but Tanaka disagrees. Locke just ignores and says “Settle that later we need to get back to the pelican”. Then they leave and stuff. Cutscene is about Buck telling Lasky and Palmer tried to do. Locke told them what Chief has become and then was stated that Chief was a traitor. Lasky and Palmer believed if it was that firing only if necessary. After that, they continued the search on how to get to Chief…Covenant…Sanghelios…Arbiter…civil war…boom. Continued on.
Reunion: First part of blue team is normal. But when they meet Warden, he tells Blue team that Cortana is alive… but he plans they dont see her as he knows that Chief was actually planning on “taking her home”. So he fights blue team and loses. Still, no sign of Cortana but Warden telling Chief was Cortana is and what she has become over the months. However, even though Cortana cant speak to Chief, she stilled open doors and bridges to show him the way he wants him to go to (Kinda like in ODST). Then boom, end of mission.
Swords of Sanghelios: Everything is fine on the mission.
Alliance: Nothing really but what Arbiter tells Locke what to expect from Chief and Locke ignores it.
Enemy Alliance: Right when Osiris was in the cave trying to get through the hiddin wall, Arbiter talks about Chief and how he experienced fighting with him and how Chief cares for others and responsibility and stuff. Like he says “Locke, I know what you really plan on facing the Chief. Yet you need to know… when I fought along side the Chief, we had our disagreements. But when I learned how he is, and what he has been through in our fight against the parasite and Covenant. Locke, I dont know what the Chief plans, but I know it isn’t how we believe it is” and stuff. Then they get to fight the Kraken…end scene…pickup.
Before the Storm: Nothing really happens but going to Arbiter and Arbiter talks about his journey and life change because of Chief. And if you stay around the area long enough, the each Osiris once in a while talks about the past on what they seen Chief do or what Chief has done for them. It just builds nostalgia of the past Halo games.
Battle of Sunaion: They fight, maybe add more dialog to the Arbiter like “I never battled like this since _____!”. And Buck was saved by Locke; making Buck trust Locke more. Then boom. mission end.
Genesis: Everything is fine from the start Warden talks to Osiris. And he believes that they can’t stop her and from taking Chief. he says stuff about Chief what Chief was doing the whole time. Like “Chief keeps resisting. But when we fully understands her work, I assure you he will soon join Cortana”. Then Osiris realizes that Chief was just being played. And THAT… is when the plan changed from custody to a rescue mission. Same thing Exuberant…tank…wardens…the Answer… mission over.
The Breaking: Everything is fine from here. Warden is sending troopers to stop Chief from meeting Cortana, Warden fails because how limited he can do when Cortana was trying to stop the Warden… cutscene… Warden clones to 100… and Cortana goes “ENOUGH” and meets Chief… bad things happen… Blue team gets imprisoned… sad… “Goodbye… John…” and mission done.
Guardians: Locke still kinda has a “Change of heart” but knows that Chief does not deserve what Cortana plans. Cortana smack talks Osiris. Locke must save Chief… yeah… bombs… mantis… Orb… save Chief… “Shes gone, sir” and end mission.
How this all plays in the end is that Cortana is lying to the UNSC/ONI/Others that Osiris betrayed as well. This makes the governors and leaders of other planets put Osiris and Blue team on KOS. ONI did that, some UNSC leaders did that. But Lasky dont really believe what Cortana is saying… but their orders was to put them on KOS by higher ranks. Even thought Lasky doesn’t want to do it, he does not have a choice.
That means Osiris and Blue team must work with Arbiter and the Swords of Sanghelios to stop Cortana in Halo 6; which it gives more fights with the Arbiter. And Palmer is with them too but since she is with Osiris and Blue team, she was considered ‘Communicating’ with the enemy and was not safe to go back to the INFINITY. Halsey as well.
How it should play in Halo 6 is Locke still has a grudge on Chief and both still had problems fighting alongside each other. But as the game goes on, they learn and adapt with each other and their beliefs (Belief trailer). So, it gives Locke more character development and more chances on being liked by the fans.
Concluding, this is how the story should have went. Has character development, matches the marketing, story is good, it is easy to understand, #HuntTheTruth, and is well executed. This is 7472 letters. Thank you for reading if you gotten this far.
They rewrite a plot at least 5 times minimum, I’m sure. Do what makes you happy - that’s definitely the most important! Like I said I don’t want to discourage you, but it’s a dangerous game to suggest that you are certain your version is better or would be better received.