This one is probably going to require a lot of work, but maybe add one or two more sizes for Asterion? At the moment we have athletic and bulky/muscular (both of which look amazing), but as we all know, everyone has different tastes. In order to better address those taste issues, I was thinking add a slim and chunky/fat option as well considering there is a fairly large audience for both.
As for minor customization's, any piercing would be interesting, heck even adding a tattoo option would be nice. An option to control how hairy/fluffy he is would be interesting too although I imagine that would be troublesome.