Super Powers

Superheroes is a hybrid genre, combining elements of sf, fantasy and action-adventure.
-copied from here. 

However, superheroes began in sf because Superman was the first superhero and his origin was extraterrestrial, not magical or supernatural. 

I mention this because there is a scene straight of Superman in Poul Anderson's "The Chapter Ends." The psychotechnician Jorun:

has flown thirty thousand light years through space in ten days by controlling cosmic forces with his own brain;

holds an envelope of air and heat around him while hanging in space, looking at Earth;

then streaks down to the North Pole.

Does he "streak" horizontally, like Superman?

Jorun is nearly a thousand years old and can will negative emotions out of his trained nervous system. That alone might be enough to qualify him as a "superman." 

These powers do not require a change of form, as discussed here. See also Getting Superman Right here.