Definitely possible. A good fanfiction in this case would depend on how well the writer combines the magical aspects of Harry Potter and the Pokémon - related elements of Team Rocket. They could make Harry a sort of mentor to Team Rocket, teaching them about honor and friendship through his Hogwarts experiences. This would not only bring a new perspective to Team Rocket but also create an engaging story that fans of both franchises might enjoy.
It would be really strange. Harry Potter is from a world of magic and wizards, while Team Rocket is from the Pokémon universe. Maybe Harry would use his magic to deal with Team Rocket's antics in the Pokémon world. For example, he could use a spell to make their Pokémon unable to attack.
One idea could be that Harry creates a school for magical creatures. He realizes that there are so many unique and often misunderstood creatures in the wizarding world, and he wants to give them a place to learn and grow. This school could teach them how to interact with wizards in a positive way, as well as develop their own magical abilities.
Yes, in some Team Rocket fanfictions, Ash can be depicted in various ways that might involve him having some sort of connection to Pokémon in a different light. Maybe he could be experimented on by Team Rocket to gain Pokémon - like abilities, or be transformed into a Pokémon - like being in a very creative and out - of - the - box fanfiction concept.
One idea could be that Harry discovers an ancient spell book in the Room of Requirement that has the incantations for creating a magic railgun. He might use it to defend Hogwarts against a new, powerful dark force that is immune to traditional magic spells.
In this fanfiction, Harry might also include some of the Hogwarts ghosts in his army. After all, they have a long - standing relationship with the school. Peeves, for example, could be a wild card in the army. He can cause chaos among the enemies. And some of the older students who have a strong sense of justice, like Cedric Diggory's friends, could also be part of it.
The plot could start with Harry finding an ancient Jedi artifact during one of his adventures. This leads him to become curious about lightsabers. He then uses his magic knowledge to try and replicate it. Along the way, he might face opposition from some in the wizarding world who think it's too dangerous or against wizarding traditions. But Harry, being the hero he is, persists. Eventually, he creates a lightsaber and uses it to defeat a new, powerful dark wizard who has emerged, using both his wizarding skills and his new lightsaber skills.
In a fanfiction where Harry Potter creates a virus, perhaps it's a virus that affects magic itself. The virus could spread through spells and start to corrupt the very essence of magic. Harry, realizing the severity, might then have to team up with his old friends like Hermione and Ron. They would search for ancient magic or rare potions to counteract the virus before it destroys the entire magical ecosystem.
In a 'Harry Potter creates a shelter' fanfiction, perhaps Harry uses his magic to create a shelter in the Forbidden Forest. He might use spells like Protego Totalum to make it safe from dark creatures. It could be a place where he hides his friends during a dangerous time at Hogwarts, like when Voldemort's forces are on the prowl.