One plot idea could be that Harry is transported to a Star Wars - like universe and has to learn the ways of the Force and lightsaber construction to get back home. Another could be that he discovers a hidden chamber at Hogwarts that contains the knowledge and materials to make a lightsaber, and he uses it to defend Hogwarts against a new threat.
If Harry Potter were to make a lightsaber, he might first need to study the principles of the lightsaber. Since he's good at researching in the library at Hogwarts, he could look for magical equivalents. He could perhaps find a way to infuse the essence of a powerful spell into a crystal, similar to the kyber crystal in Star Wars. Then, using his wand - making skills, he could fashion a hilt around it and use a spell to create the blade of light. This would be a cross - over of magic from two different universes, but that's the fun of fanfiction.
Well, perhaps Harry discovers an ancient magic that allows him to wield a lightsaber. He could use it to fight Voldemort in a more unique way, combining the magic of the wizarding world with the power of the lightsaber. Maybe he has to go on a quest to learn how to master it fully.
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.
Well, perhaps Harry Potter discovers some ancient magic that allows him to combine the wizarding world's technology with that of the Star Wars universe. He might use his knowledge of spells to power the lightsaber in a unique way, like using the Lumos spell to create the blade instead of the traditional kyber crystal. He could then face off against Voldemort with this new weapon, creating a whole new dynamic in their battles.
One possible plot idea could be that Harry, perhaps from the Harry Potter world, meets an angel in a magical or non - magical setting. They might initially be at odds due to their different natures, but as they get to know each other, they fall in love. Another plot could involve the angel helping Harry with a particular quest or problem he has, and during that process, their relationship develops romantically.
One popular 'Harry makes a lightsaber' fanfiction might be found on platforms like FanFiction.net. You can search there using relevant keywords. There are often works where Harry discovers the technology or magic to create a lightsaber in a unique crossover universe.
Well, perhaps Harry is magically transported to the realm of the dark elves. There, he has to learn their ways and magic in order to survive. He could befriend some of the dark elves who are outcasts in their own society, and together they try to change the perception of the dark elves in the wider magical world. It could also involve a battle where Harry uses his new - found knowledge of dark elf magic to defend both the wizarding world and the dark elf world from a common enemy.
A possible plot could be that Supergirl somehow ends up in the Harry Potter universe. She might use her powers to help Harry and his friends in their fight against Voldemort. And during their adventures together, she and Harry develop feelings for each other.
One plot idea could be that Mavis gets lost in the wizarding world and Harry has to help her find her way back to her own world. Along the way, they face various challenges like dark wizards who want to capture Mavis for her unique magic. Another could be that there's a threat that endangers both their worlds, and they must combine their powers to stop it. Maybe there's a powerful dark force that is trying to merge the two worlds in a chaotic way, and Harry and Mavis are the only ones who can prevent it.
In a 'Harry Potter Immortal Gunslinger' fanfiction, there could be a plot where an entire group of immortal gunslingers are sent to the wizarding world to stop a great evil. They might be from a parallel universe where magic doesn't exist but advanced weaponry does. Their immortality gives them an edge as they battle against dark forces in the Harry Potter world. They could form alliances with the Order of the Phoenix or other good - minded wizards. Their gunslinger tactics and weapons could be a new and unexpected weapon against the dark arts. For instance, they might find that their bullets can disrupt certain dark magic spells, creating a whole new dynamic in the fight against evil in the wizarding world.