I think your character looks great, but the face could be refined a little bit, in my opinion. I think her expression is leaning towards pursed lips and a slightly (very slightly) clenched jaw with a generally wide face. Neither of these are bad things in and of themselves, but I'd say that they don't come across as quite…
I liked the initial head design more. The shield looks cool, but I'd change round concaves for some interesting spikes/claws. Big shoulder pad looks a bit too flat and simplistic as well as shin protection. As for the story, the character can have regenerative abilities. So he doesn't need a lot of protection. And as for…