Another possibility is that a dark wizard in the Harry Potter world has created a spell that can bring fictional or other - worldly characters into their realm. Alexander Anderson is brought in and is mistaken for a new type of dark creature. As he tries to find his way back, he ends up helping Hogwarts students learn about self - defense in a more hands - on and extreme way than they are used to.
One idea could be a crossover where Alexander Anderson, with his combat skills and religious fervor from his own universe, is transported to the Harry Potter world. He might initially be seen as a threat due to his extreme methods, but then he teams up with the Order of the Phoenix to fight against dark wizards who are dabbling in some form of dark magic that has religious connotations in his view.
One idea could be a crossover where Naruto's world is invaded by some dark forces similar to those Anderson has faced. Naruto, with his ninja skills, teams up with Anderson, who uses his holy powers. They start to learn from each other's fighting styles and develop a mutual respect. Naruto could teach Anderson about chakra and how to use it in combat, while Anderson could show Naruto the power of faith - based combat and the use of holy relics.
If 'Harry Potter is Alexander Anderson fanfiction' were true, it would be a very odd situation. The 'Harry Potter' series is set in a world of wizards, witches, and magical creatures, with a focus on things like the fight against Voldemort. Alexander Anderson is from a different kind of story. If it were fanfiction, we might see characters like Harry Potter using abilities similar to Anderson's, which would completely change the nature of the 'Harry Potter' story. The whole Hogwarts system and the way magic is taught and used would likely be disrupted as elements from Anderson's story intruded. It would be a very different 'Harry Potter' experience, and probably not one that most fans of the original would welcome.
No way. The 'Harry Potter' series has been carefully crafted with its own story arcs, character developments, and world - building. Alexander Anderson belongs to a different fictional realm. A fanfiction implies a derivative work based on an existing one, but these two are so disparate that it doesn't make sense to consider 'Harry Potter' as a fanfiction of Alexander Anderson. They have different tones, different target audiences, and different overarching stories.
The magic in the Harry Potter world could be linked to the religious - based powers of Alexander Anderson. For example, some of the spells in Harry Potter could be seen as having roots in the same kind of divine or spiritual energy that Anderson wields. This could lead to a situation where Anderson is either trying to understand the magic in the wizarding world as a different form of his own power, or he could be trying to convert wizards to his way of thinking about the power source.
One idea could be a crossover where Harry Potter accidentally travels to the world of Clark Kent. He could be discovered by Clark, who is intrigued by this strange boy with magical powers. They might team up to fight a common enemy that is threatening both the wizarding world and Metropolis.
Another fanfiction could focus on Peeta being a Muggle - born wizard. He discovers his powers later in life, similar to Harry's discovery. Peeta's experiences in the Hunger Games could give him a unique perspective on facing challenges in the wizarding world. He might use his charm and ability to manipulate people's emotions (from his Capitol days) in a different way in Hogwarts.
One idea could be a crossover where Fenrir from the Harry Potter universe somehow gets transported to the realm of Loki. Loki, being the trickster, might see Fenrir as a tool for his own schemes. Harry Potter, perhaps in a quest to stop some dark magic related to Fenrir, ends up following him and has to deal with Loki's antics as well.
One idea could be a time - travel fanfiction where Hermione goes back in time and has to face Bellatrix in a magical duel. Harry could be caught in the middle, trying to protect Hermione. Maybe Bellatrix has a secret that could change the course of the wizarding war, and Hermione discovers it.
One idea could be a story where Dudley and Piers start to see Harry in a new light after he saves them from a magical threat in the Muggle world. They then become sort of secret allies to Harry, helping him out when he's in the Muggle neighborhood.
Perhaps a fanfiction where the Basilisk is not a solitary monster but part of a larger, more complex ecosystem in the Chamber of Secrets. There could be other magical creatures that depend on the Basilisk in some way, and when the Basilisk is in danger, these other creatures come to its aid. This would change the whole dynamic of how the characters interact with the Basilisk and the Chamber of Secrets.