@Sodium I really like your character, but I do have to point out a little issue I take with the backstory. While I think the concept of holding a tournament to select the next Prince is an interesting idea, it unfortunately does not work that way.
There is little rhyme or reason as to who inherits the powers of the Princes. Family, status, ability or even where you are born does not factor into it. The only consistency is that the powers are always inherited by an adolescent male. Other than that, the selection is pretty much random.
With that being said, it is not inconceivable that the legend of the Cosmic Princes has made it's way into small parts of human society. There can be humans who know of them and perhaps even have figured out a way to determine which boys are more likely to receive the power based on stuff like astrology and karmic destiny.
But to every other human, they are incapable of seeing the Princes, Shadows or Witches at all (While they're transformed). So the majority of the world has no idea they exist. You can still keep the concept of your characters backstory, but it will need to be edited to fit with the above information in mind.