Superhero Fiction, redux

So, in looking at genre labels, Wiki sez that Superhero is a subgenre of Fiction; so I have to feel that it is classed as its own genre, much like SF, Fantasy Horror, etc.  So my breakdown in classifying it would be much like this:

Superhero
   a) Mutation/Genetic
   b) Artifical Enhancements
        1) Temporary
        2) Permanent
   c) Alien/Extraterrestrial
   d) Villian

Any additional suggestions/comments/enhancements?