wtf do you think your doing with that first one? You think that because they said that chronologically forward unto dawn, the first failure child of 343, a series that came out after halo 4, happens before Halo CE, so you think that that means that it would be appropriate to put him there, even though his armor has more detail and then the Halo 4 armor?
You really think thats ok? Because its not. For 1000 reasons its not
the reason why chief is wearing a poncho it's to protect his armor of the sand (the sand and the metal are not a great combination) so it wont get more damaged than it is already, i believe he will use the poncho in the first mission of the campaign, cuz they dont want the fans to blame poncho chief lol
It Depends of the damage in the metal if its way very very old and damaged the metal would start to turn more fragile and start tearing apart, if is not so damaged there is a good chance that the armor may resist a while the low temperatures, if the person who is wearing is not near of a heat source the armor will turn into its tomb, also it depends much the kind of metal that the armor is made of
Actually coming from a person who has read nearly all the Halo books, the shield protects from everything. It's always there, always on. I remember reading about one part where after the shields were implemented (from stealing the technology of the jackal shields) that it took time for the Spartans to get used to interacting with things, because the shield is a barrier and it's always on. It protects from everything physical, even below the feet.
I feel like you underestimate mjolnir armor a bit. First of all those energy shields will protect the wearer from much more than energy based weapons. Think a minute, how come they block bullets and melee? Simple, they also deflect kinetic threats. While the threat of sand is ever present due to abrasion wearing/damaging armor, if a bullet can't get through its shields it is doubtful sand will. Even falling damages energy shields. In addition, its rare that we see his armor beimg dirty in canon, most likely due to shields having mo problem deflecting nature. The only thing that could really endanger his shields are sandstorms. A bit of sand/dirt impacting your shields will do nothing if a magnum round is what it takes to bring your shields down an inch. But a sandstorm may potentially get through. At the same time, wearing a poncho would be useless as it'd tear right through. As for temperatures, how many times has John-117 been in the vaccum of space? If you don't count the time he locked his armor on re-entry, he still has been exposed to the great void. The temperatures in space are much more lethal than anything on a habitable planet, exceptions to maybe magma. The armor was designed to fit all conditions, including extremes. The most reasonable answer for why h wears a poncho comes from outside in-game lore. The trailer tried to conceal John's identity. They had to make it look at least fitting for someone who doesn't wear top-of-the-line armor. (Apologies for typos, this is on mobile)