Some element within the UNSC or other human interest wants to capture MC and harvest his DNA in order to take humans on their next evolutionary step, or to prevent devolution (if you can call it that). This will probably be explored in the halo tv series, especialy considering the biggest objection to the halo movie was that the protagonist had no face so couldn't convey emotion and his adversaries were pretty much expressionless too. Whether with or without Halsey, MC goes on the run and you end up fighting a variety of human, covenant etc, perhaps with help from the Librarian. I think maybe that explains the cloak, and why the machine rising out of the sand doesn't attack him, but seems to side with him.The narrative in Halo 4 seemed to allude consistently to the dangers of the human race's continued expansion. I think MC is really some kind of self-defence mechanism for stopping this happen, and the Didact was a smaller cog in a much bigger story. Or in other words, the Librarian is playing one big deception and supporting MC in order to prevent chaos in the future (as she does recount the history of this happening before).
