About Himiko - I guess it is not so obvious that she is a Mary-Sue parody because in a way she has too much personality on her own. ^^
And yeah, for me it is always very important to keep the characters as in-character as possible even if they sometimes do silly things. After all, if one writes a fanfiction, for me it means keeping the canon characters recognizable. For me the question is always "Can someone believe the character XY would do such a thing?"
You could consider setting up an account at deviantART - there you can present your artworks nicely and get even more critique (there are quite some Saint Seiya fans, too).
Well, the main problem is that I lost contact with my co-author. And as he did such an amazing work portraying Astrios, I doubt I could do it on my own. -_-'
Thanks a lot! Now I just need to figure out a consistent way to draw hands and feet well. At the moment it is more sheer luck if I get them right. -_-'