Why is Fu the real protagonist?

He has a lot of wandering plots, more than his sister, and it is a very positive image.

He has an intersection with the protagonist's sister. In some fights, the protagonist loses, and the sister will run with him.

And he also has an intersection with the devil, regardless of good and evil, follow the feeling and make a Ling Huchong template.

He is a good martial arts teacher. The protagonist of the Junior Heroes' Club will win the championship if he doesn't win it.

He has some good drinking friends, and all of them are friends of life and death, which makes the protagonist extremely envious.

Dig deep into the plot. His father is a great swordsman. Although neither side knows it, it is necessary to be born.

Handsome, well-born, talented, martial arts, open-minded and feminine. .....

What is such a person who is not the real protagonist?