At the end of Halo 5 Cortana has the entire galaxy on lockdown with only the Infinity left to fight, chief and the rest are all on Sangheli. Halo Wars 2 ends with the new ring and Anders facing a Guardian. jump into Infinite and Chief gets taken down by Atriox and the Infinity gets destroyed. how/when/where/why? don't know (having finished the game i STILL don't know) somehow EVERYONE found Zeta Halo, Chief goes in to retrieve Cortana but fails (unclear exactly how) and gets taken out by Atriox and floats around in space for 6 months. HOW did he survive? don't know stop asking questions.
Where is Halsey? Lasky? Blue Team? Fireteam Osiris? Arbiter? don't know again stop asking questions. we're introduced to The Weapon. a clone of Cortana just like she said they would. this one though is new unsure of herself and very........bubbly, not GOOD bubbly more like that weird girl in class bubbly. so we find that Atriox is dead HOW? don't know. and we're introduced to generic bad guy what's-his-face an olog from Shadow Of War that found himself in Halo. along with him there's the Angel woman from DOOM Eternal. and they're doing THINGS. mysterious things, DANGEROUS things.
all the while John is hearing a disembodied Cortana whispering to him. i'll be honest this is the only time i felt emotionally invested. when Cortana was talking. that's it. that is how little i care about everything else. in the end Cortana realises that she made a mistake. how? how did the woman with all the power in the universe make a mistake? oh Atriox beat her HOW? don't know gonna need you to get ALL the way of my back.
she sets up a message telling Chief how sorry she is and how NOT Cortana is the future blah blah blah then done. she fades away. ignoring how the cringy faces Cortana and her weird sister are just disturbing they completely ruin the emotion of the scene. in the end Cortana the heart and soul of Halo is dead. and in steps this newer "better" version.
i think i may actually be done with Halo. i grew up with Halo i've been here since the beginning. Since Halo Combat Evolved. and now after all these years over 20 years i think i'm done. Cortana's death in Halo 4 is still to this day heartbreaking. but seeing what they've done to her. how badly they've handled her since Halo 4 just i'm done. 343 could no SHOULD have spent Halo 5 having Chief work through the pain and emotional heartbreak of Cortana's death to slowly realise how much she meant to him only for the game to end with Chief learning she's alive and rushing off to save her.
Halo 6 or Infinite could then have been about Chief going through emotional hell to save her watching her suffering pushing past everything to get to her. THAT would have been FAR better than the mess we've had with Guardians and now Infinite.