One plot could be that a hidden order of Grey Jedi has been secretly observing the wizarding world for centuries. When Harry Potter shows signs of being a special kind of wizard, they decide to make contact. They teach him their ways, which include a more balanced approach to magic. Harry then uses this new knowledge to not only fight Voldemort but also to reform the wizarding world's view on magic. He might try to end the long - standing feud between pure - bloods and half - bloods or muggle - borns, seeing all as equal in the eyes of this new, more inclusive magic that combines the best of both the Grey Jedi and the wizarding traditions. This would lead to many adventures, challenges, and character growth for Harry and his friends.
A possible plot could be that a Harry Potter character discovers an ancient magic that has similarities to the Force. They then start to develop abilities and a moral code similar to Grey Jedi. They might face opposition from both the wizarding world, which is used to the traditional light and dark magic, and some dark forces that see this new power as a threat.
Well, the plot could involve a transfer student from another dimension (where Grey Jedi exist) coming to Hogwarts. This student brings with them the knowledge of the Grey Jedi way. As they interact with the Harry Potter characters, they start to influence them. Harry, for instance, might be intrigued by this new way of thinking and start to question the black - and - white view of good and evil magic in his world. There could be a big conflict when Voldemort tries to either recruit or destroy this new element in the wizarding world.