OK so follow this idea ...
A character has its gene pool, and if he wants to stay younger and develop itself he has to find other character (perhaps opposite gender

) and then if both characters want to exchange genes - they can do it (under special conditions) then both characters mutate - become younger and change their -... stats, apperance etc...
Just need to develop proper \"special conditions\"
Such game would be much more social, much more intriguing than simply bashing monsters to gain experience...
It was game called \"ECO\" long time ago - similiar idea was used, and the game was very addictive...