So I'm trying to write a fanfiction. Urban fantasy. Gods, demigods, magicians, and god-killers. The name is Campione. https://en.wikipedia.org/wiki/Campione! One fellow. Hot headed. But extraordinarily powerful. Powerful enough to wipe out armies as a starter. He's someone incredibly ignorant of the power structure of the world. He's capable of speaking... but he's not a glib speaker, nor a very convincing liar. He's near incapable of politicking. He doesn't know the wider magical world he's in. He doesn't know who's who. Who to avoid, and who to talk to. What rules to follow. Various history and context. The other is a girl. Born of a dynasty ruined by a run in with one of the setting's big names. Home looted of all valuable artifacts. Family bereft of allies after they fled in fear. Army scattered to the winds, after their defeat. Majority of her family dead, except for one mad mother. Left to die in a mansion slowly rotting from lack of maintenance. Forced to recover her family's secrets from worn out tomes, reading by nightlight. Practicing from old scrolls, using a rusting sword, with no magic. Teaching herself magic, because everyone else was dead. But she knows. Her family name has prestige and can open doors, if only the hinges were oiled with money. She knows enough about the politics and organizations of the moonlit world to fit entire libraries, passed down by the few who survived. She knows how to talk herself out of trouble, to navigate the halls of power and politics. To see the lines and links between humans and force them to dance on strings. Problem. She's an average fighter. And political legitimacy comes from the barrel of a gun. And all the talk in the world wouldn't help you when a thug is coming at you with a knife. And she's in a catch 22 situation. She needs power, to accumulate power. But now she has no power at all. She needs someone who's loyal to her, can't be bought off, and is powerful enough to face down any threat. In comes the boy. Their first meeting comes upon the hunting down of a rogue mage with a bounty on his head for theft. Not because of the experiments he runs on human beings. Not for his tendency of kidnapping people off the street. For theft. They kill him.... and decide to join forces. The girl for power. The boy for protecting the innocent, and the girl being a source of information and connections. Together, they will make a legend that will rock the world on its axis. I wish to write them both, with both of them being protagonists. The girl, as a social character, the boy as martial. Both are of equal importance. Both are to contribute. Both are to be valuable members. How?
I assume this will be a short story, not novel length fan fiction. Limited space means that you'll need to convey your characters with fairly minimal dialogue that paints a picture of their relative social tendencies and do the rest of the work with exposition. I would write it from the girl's POV, as her thing is more subtle and that will give her perspective more 'screen time' to illustrate it. But that doesn't mean the boy can't be her equal - you'll just need to give him more activity to make up for the decreased perspective.
My advice: write it by writing it -- you won't really know the story until you put it down in words. Then balance it, if necessary, by revising it. Bring to the Workshop (if it's not too long) and ask people about the balance. Also, there's two different ways they can be important: to the story, and to the reader. Which are you after -- you can have one without the other, if you want.
I'm planning on making it long. Quite long. Story. If the reader can't grasp the nuance, that's their problem.
Re: two different ways characters can be important: to the story, and to the reader. Okay, but realize a character can be the most important character in a story and barely ever appear in it. For example, Sauron in Lord of the Rings.
Have you considered putting all that effort into writing something original so it could be published? In any case, what does the Campione region have to do with fantasy, or is that the wrong link? And I would still encourage you to write from the girl's POV as your description of the boy makes his motivations more obvious.
Weird, you mean the manga, right? Every one of your links opens wrong, as it did when I tried to post it.
Son of a- Yes. That's the one. Sigh. When I said Campione, I mean the light novel. It was the first light novel I ever read. It holds a special place in my heart, and so I wish to write a fanfiction about it.