Looks good but it would look better if done using Zbrush or 3ds Max
The helmet's dome doesn't flare out and then angle back in - it just flares out. Take a look at the back of the profile view. The angle that you're seeing from the front is its curved bottom as it wraps around back because the head is lowered at and angle.
I think Kylo Ren's mask can be built from Army of two templates. I may be wrong but they have many structural similarities.
Before you proceed any further may I ask you if you have seen the new concept arts released? Your pdo's head and eyes are quite spot on but the mouth piece is different.The outer part of the eye sockets is too big on the Army of Two masks, but the rest is pretty similar.
Here's a screenshot of the initial PDO development. I'm thinking that it'll be too narrow.
View attachment 466667
Actually I saw them the same day I started working on the version I have *facepalm*. Everything below the eyes is pretty much completely different. I really like the details on the cheekbone area, though I'm not sure they'll translate well to a PDO.
You would have to do the cheekbone area as a separate layer that lays on top of the bottom layer of mask. In fact this mask is all about layering. You have the bottom layer, the chrome detail layer, a bottom mouthplate layer, and a top mouthplate layer. And that's just the front
That gives me an excellent idea. It might be easier to just make a template for foam instead, and cut each layer from an appropriate thickness.