From my knowledge, that part of the armor is named a Glancer. It is a rare addition to armor because they are often heavy and cause an offset of weights on the front side of the body.

The reason its nickname is a Glancer is because it causes the attacker to glance a blow on the defender when they are aiming for the upperbody and neck.

This basically means bladed weapons (and possibly some blunt) slide off the focus area. The issue found with this particular design though was that where the metal folds are, it gives a stab a lot more possibility for damage because their weapon can slide to the fold and pierce through there. Which is why it looks great, but is often not used in functional armor replicas meant for combat.

It has it's Pro's and Cons i guess.

Upper-cut deflector?

It's to collect rain water in case they get thirsty in the heat of battle.

I nearly pissed myself reading that.
Congrats, win comment.

this is where his holographic hud come out of

Nothing. You see the plate protecting the throat directly above it.
The whole suit is ridiculously impractical.

Exactly what I was thinking.

Fucking stab the shit out of someone's face

It throws the enemy off guard because it looks cool

it's to prevent dirt splattering on your helmet, when you're driving really fast.

i think it was based off early jousting armor, and that kept the lance from getting under their helmet.

don't hold me to it though, it's just a theory

I kind of thought about that.. but after looking up typical jousting armors... the helmet itself is made in such a way that the lance CAN'T get under the helmet.

.. and after looking at other kinds of medieval age armor.. this design seems to never be used.
I'm going to chalk it up as a completely aesthetic design the Japanese threw in to make him look cooler for the show. And there's evidence to it because.. you know how much the Japanese love making armor designs look cooler rather than have any actual functionality.

Probably so no one can sweep upward with a sword and cut your head off