It could be an original character created specifically for this fanfiction. Maybe a young wizard or witch who has always been an outcast in the wizarding world and discovers their unique ability to connect with dark dragons.
There's also a possibility that it could be a character who was experimented on by dark wizards. The experiments somehow gave them the power to be a dark dragon master. This character would then have to deal with the consequences of their new - found powers and the stigma associated with being related to dark magic.
Harry Potter himself could be the main character. Imagine him stumbling upon a dark keyblade and having to grapple with its power. He would have to decide whether to use it to fight Voldemort or risk being corrupted by its dark influence.
Maybe it's an older wizard who has been studying arithmancy in secret for years. He decides to come out of the shadows and share his knowledge at Hogwarts, becoming the central figure in the story as he mentors the students and uses his skills to solve various magical problems.
A Muggle - born student could be the main character. They might not have the same preconceived notions about magical beasts as the pure - bloods and half - bloods. Their fresh perspective could lead to new ways of handling and understanding the beasts. They could be the one to discover a new breed of beast that has been hiding in plain sight, right on the outskirts of Hogwarts.
Perhaps it could be an older version of one of the main characters from the original series. For instance, an adult Harry Potter who has become a master of certain types of magic and is now on a new adventure. He could be traveling to different parts of the wizarding world to teach or to learn more advanced magic techniques. Another possibility is that it could be a character like Dumbledore in his younger days when he was on his own journey to become the great wizard he was known to be.
It could be a new student at Hogwarts who discovers their talent for runes early on. Maybe they come from a family with a long - forgotten tradition of rune - making and they are the first in generations to revive it.
Hermione could also be a great main character. Given her thirst for knowledge, she might be the one to first study and understand the concept of Haki in the fanfiction. She could then use it to her advantage in battles and also to help her friends, perhaps even using Haki - enhanced magic to break through difficult spells or magical barriers.
Perhaps it could be a well - known character from the original Harry Potter series who discovers a new aspect of their magic. For example, Hermione might find that she has an aptitude for seal magic while researching some ancient texts in the library. She could then use her knowledge and newfound ability to solve some of the problems in the wizarding world.
It could be an original character created specifically for the fanfiction. Maybe a young wizard or witch who discovers their Shadow Master abilities by accident.
It could be a new student at Hogwarts. A young witch or wizard who has always been fascinated by dragons and finally gets the chance to encounter one and become a rider. This character could bring a fresh perspective to the Hogwarts world.
Bellatrix Lestrange could be a potential focus as a dark arts master in fanfiction. She already has a deep knowledge of the dark arts in the original series. Fanfiction could explore her even more, perhaps showing her training others in the dark arts in a more in - depth way.