Both Colin White and Justin Wyat gave similar advice regarding character improvements. Apparently hero's and villain's heads had "problems", one looked like clayed onto design and another failed to convey the personality correctly. So having put some thought I came up with some ideas.
I had to make hero more human-like, so the audience could empathize with the character more and recognize him as "the good guy"
And for the villain, quite simply ( and I don't know why I didn't do that from the beginning) I just had to keep the same design logic with the head as with his body - more edgy, sharp triangular shapes.
I'm not quite sure if these are working perfectly, I wouldn't hesitate to change anything if it be more communicative. So I guess I’ll wait for some feedback or a good idea to come.
Other than that, this week’s assignment was to write a dossier for each character, sketching out whatever detail might be important.
And I quite used it. Before drawing test expressions I’d read it so to respond to it when creating expressions. So further follow few examples of that for each character. I didn’t want to rush myself with this, since really, I’m only beginning to get to know my characters, their construction. It does take a while to get your head around their shapes and how they’d change in a particular reaction… I felt my brains swollen…:D