Wikipedia says
A superhero or superheroine is a stock character that typically possesses superpowers, abilities beyond those of ordinary people, and fits the role of the hero, typically using their powers to help the world become a better place, or dedicating themselves to protecting the public and fighting crime.
So yes, he is definitely dedicated to protecting the public, but it feels wrong to call him a super hero. What do you think?
It’s just a step removed. He’s from an order of space wizards basically, similarly to how Harry Potter hails from an order for regular wizards. Both groups tend to qualify as superheroes for the most part, but are usually referred to by the subgroup, as opposed to the more general categorization.
Another more traditional, yet similar example, would be the Green Lanterns or Marvel’s wizards. Space wizards and regular wizards respectively, but clearly superheroes due to hailing from well-known purveyors of superhero media. Structurally and mechanically similar, though.