In developing the plot, imagine Harry Potter being reborn as a sort of wizard - Lelouch hybrid. He might start to question the traditional ways of the wizarding world, much like Lelouch questions the rule of the Britannian Empire. He could use his knowledge of both magic and Lelouch - style strategies to undermine Voldemort's power. For instance, instead of just relying on the Order of the Phoenix, he could create his own network of allies, some of whom might be from unexpected places in the wizarding world. He could also use his magic in creative ways to gain an upper hand, such as using transfiguration spells to create strategic advantages similar to how Lelouch uses his resources in his battles. This would completely change the dynamics of the Harry Potter story and add a whole new layer of intrigue and action.
One way could be to give Harry the Geass power. So, he could use it to control the actions of Death Eaters or Voldemort himself. He might start to make more strategic and calculated moves like Lelouch, using his new power to outwit his enemies. Another aspect could be in the political side. Maybe the wizarding world becomes more like Lelouch's world with different factions vying for power and Harry has to play a political game as well as fight against the dark forces.
Well, to develop the plot, we could start with Harry having a vision similar to Lelouch's about changing the wizarding world. He then begins to form his own group, like Lelouch's Black Knights. He could use his magic in a more tactical way, inspired by Lelouch's use of his Geass and military strategies. For example, he could use spells to create illusions on a large scale like Lelouch uses his Geass to deceive his enemies. Also, there could be a conflict within the wizarding world where some people oppose Harry's new - found 'Lelouch - like' ways, creating internal drama and power struggles.
The plot could start with Harry having strange dreams about Shinigami. As he investigates, he discovers that there is a hidden portal in Hogwarts that leads to a realm where Shinigami exist. He and his friends enter this realm, and they find out that there is a dark force in the wizarding world that is related to the Shinigami in some way. They then have to work with some friendly Shinigami to stop this dark force. Along the way, they learn about new forms of magic and the true nature of death from the Shinigami.
The plot could start with a spell gone wrong in Hogwarts that somehow transports a group of Transformers to the wizarding world. The wizards are initially scared but soon realize that they need to cooperate with the Transformers to deal with a new dark force that is attracted to the combination of magic and technology. The story could involve battles, magic - tech hybrids, and new friendships between the two groups.
One way could be to have Harry be adopted by a Mandalorian family. He grows up learning both magic and Mandalorian combat skills. Then, he has to use his combined knowledge to fight against a common enemy that threatens both the wizarding world and Mandalore.
One way it could work is if there was a magical portal that connected the wizarding world to Spider - Man's universe. Harry could accidentally stumble through it and then get involved in Spider - Man's battles, using his magic to help out.
One way could be through a plot where Harry discovers some long - hidden secrets about Dumbledore that he feels were manipulative. For example, if he found out that Dumbledore had been using him more than protecting him all along. Harry might then confront Dumbledore publicly in the wizarding world, shaming him for his actions.
One way it could work is if Jack Sparrow somehow ends up at Hogwarts. Maybe he's chasing a magical treasure that has been hidden there. His pirate ways would clash with the strict Hogwarts rules, and Harry Potter and his friends could either befriend him or be suspicious of him. Another possibility is that Harry Potter, being a fan of Jack Sparrow, tries to model some of his actions after the pirate, much to the dismay of his teachers.
One way could be that Godzilla somehow appears in the wizarding world. Maybe a magical experiment goes wrong and transports Godzilla there. Then the wizards and witches have to figure out how to stop it using magic.
Well, one way could be through a magical accident. Maybe a spell gone wrong during a battle or some kind of experiment that binds their magic in an unexpected way, leading to the creation of a child. It could also be a result of a forced situation by a dark force that wants to see the two rival families united in a very strange way.
To develop it, you could introduce a new character who is a hybrid of a wizard and a Cybertronian. This character could be the link between the two worlds. Harry could then be drawn into the Cybertronian world through this character. In the Cybertronian world, Harry could discover that magic has a different manifestation. He could learn to combine his magic with the technology of the Cybertronians. For example, he could use his wand to control the energy flow in a Cybertronian's body, or use a spell to enhance a Cybertronian's weapon. The story could also explore the ethical implications of mixing magic and technology, and how it affects both the wizarding world and the Cybertronian society.
One way could be that Harry is somehow transformed into a RoboCop - like figure in the wizarding world. He could use his new robotic powers along with his magic to fight against dark wizards. For example, his robotic enhancements could give him super strength to physically combat opponents, while his magic could be used for more complex spells.