Another plot could involve the creation of a female monster. In the original, Victor Frankenstein was hesitant to create a female. A fanfic could explore what would happen if he did. Maybe the two monsters would have a complex relationship, and together they would try to find a place in the world that would accept them.
A third idea is a time - travel plot. The monster could be sent back in time to the era when he was first created. He would have the knowledge of the future and could try to change his own fate. He might attempt to convince Victor not to abandon him, or he could try to find a way to make himself more acceptable to society from the very beginning.
Perhaps a fanfic could explore a scenario where Rai has to pretend to be a normal human for some reason, and Frankenstein has to help him blend in. This would be full of comical moments as Rai tries to understand human customs and behaviors, all while Frankenstein is there to keep him out of trouble and protect his true identity.
One idea could be that the OC is a healer who stumbles upon Frankenstein's monster in the woods. The OC decides to help the monster, despite the danger, and they form an unlikely bond. This could lead to a story of redemption for the monster and a journey of self - discovery for the OC.
One idea could be that Rai, with his unique powers, somehow stumbles upon the re - animated creation of Frankenstein. They initially see each other as threats but gradually come to understand that they both are outcasts in a way. Rai could use his powers to help Frankenstein's creature control his more violent tendencies. Another plot could involve them teaming up against a common enemy, like a mad scientist who wants to use both of them for his own evil experiments.
One idea could be that Orochimaru tries to create a Frankenstein - like being using ninja techniques and DNA from various powerful shinobi. He might mix the strength of the Uchiha's Sharingan with the brute force of the Akimichi clan. Another could be Naruto accidentally stumbling upon a hidden laboratory where a mad scientist - type character is creating a Frankenstein creature. The creature could initially be hostile but then form an unlikely bond with Naruto as he shows it kindness.
One idea could be to combine the magic of Harry Potter with the concept of creating life in Frankenstein. For example, a Hogwarts student could attempt to use magic to bring a creature to life in a similar way to Frankenstein's experiment, but with magical twists. Maybe they use a spell on a patchwork of magical creatures' parts. Another idea is to have a character from Frankenstein's world end up at Hogwarts and deal with the magical environment and its rules, while also bringing their own knowledge of creating life.
Another plot could revolve around the characters having premonitions of the events that are going to occur in the quarry. They then have to decide whether to trust these visions and how to act upon them. This could add a whole new layer of suspense and mystery to the story.
One idea could be a time - travel plot. The Backyardigans accidentally find a magical object in the backyard that sends them to different eras in history. They could have to work together to find their way back home while also learning about the different time periods. For example, they might end up in the prehistoric era and have to deal with dinosaurs.
One idea could be a story where one of the dalmatian puppies gets lost during a family outing and has to find its way back home, facing various challenges along the way.
One idea could be exploring the backstory of a minor character in the Bioshock universe. For example, a splicer's journey before they became spliced. It could show how they were once an ordinary citizen of Rapture and what led them to make the fateful decision to use ADAM. Another plot could focus on an alternate timeline where the protagonist makes different choices. Maybe they side with the wrong faction and have to deal with the consequences. A third idea is a story centered around a new type of plasmid that has unexpected effects on the user and how it impacts the power dynamics in Rapture.
One idea could be that Batman and Wonder Woman team up to stop an ancient, otherworldly threat that's beyond the capabilities of the Justice League alone. They have to travel to different dimensions and rely on each other's unique skills.