>>Though in descriptive terms, "nefil" is a metapower like "Kryptonian" is -- one source that can yield many different abilities.<<

Isn't that true of any species? I mean, no human has full access to all of the possible human abilities. (Trapeze artist, bodybuilder and painter are all vastly different skills...) Granted there will be a lot that almost everyone can do...most humans can walk, vocalize and do fancy stuff with our hands.