In the new E3 Trailer for the upcoming Halo game (not sure if its 5 yet.) -> http://www.youtube.com/watch?v=blW40AVWXrE
People keep complaining on why Master Chief is even wearing a cloak since his armor should filter and protect him. But He doesn’t have all of his armor on and therefore no power to filter anything. He is only wearing what little remains of his armor. So he is wearing a self made (I’m guessing.) cloak to protect himself from the sand and elements. Also I may be looking to deep into this but the whole trilogy (Halo 4-6) is about John finding his Humanity and for the entire first trilogy, Cortana was his humanity in a sense and with Cortana gone he is on his “Journey” to find her and his humanity and his armor is the personification of what he used to be a “war machine” so he is slowly losing his machine likeness to a more human personality.
I expect more emotion from John in Halo 5 and 6 because of this.