I missed this one when re-reading. You realise what you've started? Again?
Yeah. Sonic is SUPPOSED to be relatively flat. So is Dr. Robotnik.
Shadow was SUPPOSED to be deep, intriguing, mysterious, dark, edgy, and all the other buzzwords that gives angsty teenagers instant erections. They failed utterly and miserably at it. (except, of course, to the aforementioned angsty teenager crowd)