What are some interesting plot ideas for a Siren's Lament crossover fanfic?

One potential character could be Harry Potter in a crossover with a magical world. The sirens' powers might be something new and dangerous that he has to face at Hogwarts. He could use his magic skills to try and counter the sirens' alluring voices. Another character could be Katniss Everdeen from The Hunger Games in a post - apocalyptic crossover. The sirens could be part of the Capitol's new weapon, and Katniss would have to find a way to fight against them. And in a crossover with a pirate - themed story, Captain Jack Sparrow could be included. Jack's wily nature might make him both a target and an ally of the sirens.

It could be about various things. Maybe it focuses on original characters (OCs) within the context of the 'Siren's Lament' world. It might explore their backstories, relationships, or new adventures in that universe.

As it's OC (original character) fanfiction, the main characters would likely be the original characters created by the fanfic writer. However, they might also include some of the canon characters from 'Siren's Lament' to interact with the OCs.

Another option is a crossover with the Pokémon world. The Phantom Thieves could travel to a region in the Pokémon world and discover that someone is using Persona powers to make Pokémon act out of control. They would need to catch Pokémon themselves and use their combined powers of Personas and Pokémon to stop the bad guy. It would be interesting to see how they interact with Pokémon trainers and the whole Pokémon ecosystem.

A cool plot could involve the Persona 5 crew going back in time to the events of Persona 3. They might end up interfering with some of the original events, which could have unforeseen consequences. For example, they could accidentally change the way a key character in Persona 3 awakens their Persona, and then have to figure out how to fix it while also dealing with the Shadows in that era.

One idea could be to cross it with another popular RPG. For example, having the Persona 4 characters enter the world of Final Fantasy. They could interact with the different races and magic systems there. Another could be a crossover with a detective - themed anime. The Investigation Team could team up with the detectives from that anime to solve a mystery that spans both worlds.

Another plot could involve a crossover with the Punisher and the X - Men. Frank Castle might find himself in a situation where he has to work with mutants. He could initially be distrustful but then realize they are fighting for a similar cause against a common enemy that is targeting both humans and mutants. For example, a group of anti - mutant and anti - vigilante fanatics.

One idea could be a crossover with Peter Pan. Tinkerbell could meet characters from another world, like Alice from Wonderland. She might be confused by the strange rules and creatures there, and her magic could interact in unexpected ways with the Wonderland magic.

Another plot could involve a crossover with a post - apocalyptic world. The Boys find themselves in a world where society has collapsed, and they have to team up with the survivors against new threats. This could bring out new sides of the characters as they are forced to adapt to a completely different environment and face challenges they've never faced before.

One idea could be to cross over the characters from 'Percy Jackson and the Olympians' with those from 'The Kane Chronicles'. For example, the demigods and the magicians could team up to fight a common enemy that threatens both the Greek and Egyptian mythological worlds. Maybe a new dark force that has the power to disrupt the balance between the two realms.