One possibility is that Harry would completely change the curriculum of the Dada class. Since he has a different perspective compared to previous teachers, he could focus more on mental defenses against dark magic. He might teach students how to resist the Imperius Curse by using their own willpower and positive memories, something he had to do many times.
In the 'Harry Potter becomes Dada teacher' fanfiction, he could bring in his friends as guest speakers. Hermione could talk about the theory behind spells, while Ron could share his experiences of facing fears in the wizarding world. Harry would also create a more inclusive and hands - on learning environment, allowing students to practice spells in a more real - life - like scenarios.
Well, in this fanfiction, Harry might use his own experiences with dark magic to teach in a very practical way. For example, he could share how he faced Voldemort and his Death Eaters and turn those real - life situations into lessons on defensive magic. He might also introduce some new spells that he has learned or developed during his adventures.
Perhaps Harry would try to make the DADA classroom a more inclusive and safe space. He had faced so much discrimination and danger himself when he was a student. So he would ensure that no student, whether they are Muggle - born or pure - blood, would feel left out or threatened in his class. He could also use his Gryffindor courage to inspire students to stand up against any form of dark arts or bullying.
Maybe the new Dada teacher was once a student who was deeply affected by a dark magic encounter. So, he came back to teach DADA to make sure no other students have to go through what he did.
Perhaps Harry Potter becomes a teacher of Quidditch. He was an excellent Quidditch player himself. He would train the students in new strategies and techniques. He could also share his experiences of playing in important matches. He might organize special Quidditch tournaments within the school that have different rules and challenges compared to the regular ones, making the sport more interesting for the students.
Well, he might completely change the power structure in the wizarding world. He could rewrite the rules at Hogwarts, for example, making it more focused on combat training against the dark arts. He might also form a new alliance with the magical creatures, using their unique abilities to strengthen his rule.
Harry could also be a great Quidditch coach. He was an excellent Quidditch player himself. He would be able to train students in the skills of flying, teamwork, and strategy. He could pass on his love for the sport and perhaps even lead the school team to many victories. He would know how to spot potential in young players and help them develop their talents.
In a Harry Potter becomes a Pokemon fanfiction, Harry would likely bring his Gryffindor courage to the Pokemon world. He could be drawn to fire - type Pokemon like Charmander because of their similar fiery spirits. He might also use his invisibility cloak to his advantage while exploring the Pokemon habitats. Harry would probably try to understand the Pokemons' powers and abilities in the way he learned about magic at Hogwarts. He could also introduce the concept of houses to the Pokemon trainers he meets, creating a new kind of bond among them based on the values of Gryffindor, Hufflepuff, Ravenclaw and Slytherin.
If Harry Potter becomes a lantern fanfiction, there could be some really interesting crossovers. Maybe Harry could use Green Lantern's power ring in the wizarding world. He might use it to create magical constructs that combine with his spells, like a Patronus made of green energy. It would change the whole dynamic of his battles against Voldemort and his Death Eaters.
Well, he may face a lot of challenges at first. The other Gryffindors might view him with suspicion. However, as a Slytherin, Harry could start to explore the more complex magic that Slytherin students are often associated with. He might befriend some of the pure - blood families in Slytherin, which would give him a different perspective on the wizarding world's politics. And he could end up being a bridge between the two houses that are often at odds in the original story.
In such a fanfiction, Harry Potter as a Hollow might lose his sense of self and humanity. He could be driven by basic instincts rather than his usual moral compass. This would likely lead to a very different dynamic in the wizarding world as his friends would be faced with either trying to save him or having to oppose him.
In such a fanfiction, Harry might discover new powers related to being a monster. For example, he could have enhanced strength or senses. Maybe he would struggle to fit in with his old friends at Hogwarts as they might be afraid of his new form.