There might be a Xander - centered crossover fanfiction where he enters the 'Harry Potter' world. He could bring his knowledge of fighting the supernatural from his own world to Hogwarts. Maybe he'd help the students there deal with some dark magic threats that the teachers are having a hard time handling. This type of crossover can create really interesting storylines as Xander's different perspective and skills add a new dynamic to the wizarding world.
You should also do some research on both universes. If you're crossing Xander with the 'Doctor Who' universe, know about the rules of time travel in Doctor Who and how Xander's normal life in his own world would be affected by it. Then, start creating a plot that involves Xander as the central character. Maybe he gets accidentally transported to the Doctor's world and has to find a way back while also helping the Doctor save a planet or something. Build up the story around his experiences, his reactions to the new world, and how he uses his own abilities to get through various challenges.
Another common theme is the clash of different mythologies. The show Xander is from might have its own set of supernatural rules and creatures, and when combined with the Supernatural world, there are a lot of interesting interactions. This can lead to stories where the characters have to figure out how to deal with new and unexpected threats that come from the combination of these two different mythologies.
One great Xander crossover fanfiction could be one where he crosses over into the 'Buffy the Vampire Slayer' and 'Supernatural' universes. It might have him teaming up with the Winchester brothers to fight vampires that are a bit more complex than the ones he's used to in his own world.
A 'xander crossover fanfic' typically refers to a piece of fanfiction centered around a character named Xander. Fanfic authors create these crossovers to explore new and interesting scenarios. In this case, it could be that Xander, who may have his own established backstory and characteristics in his original source, is made to interact with different characters, settings, and storylines from other fictional works. This can lead to really creative and unique stories, such as Xander forming an alliance with characters he would never meet in his original story, or having to face new challenges that test his limits in ways that the original story didn't.
One popular Xander slash crossover fanfiction might be one that crosses over with 'Buffy the Vampire Slayer' and another supernatural show. It could explore a romantic relationship for Xander in a different, yet related, fictional universe.
Begin by brainstorming how Xander's personality would fit into the new setting. If it's a crossover with 'The Lord of the Rings', Xander's courage would be a great asset, but his modern - day thinking might clash with the more traditional values of Middle - earth. Develop a conflict or goal for him in this new world. It could be that he has to help Frodo get to Mordor in a different way than in the original story, using his own skills.
The uniqueness of 'bottom Xander Harris crossover fanfiction' lies in the combination of characters from different universes and the specific role of Xander Harris as a 'bottom'. It allows for new relationship dynamics and story arcs that wouldn't exist in the original shows or stories.
You can start by looking on fanfiction.net. It has a large collection of fanfictions, including many xander harris crossover ones. Just use the search bar and type in 'xander harris crossover' and you'll get a list of relevant stories.
One good xander harris crossover fanfiction could be the one where he crosses over into the 'Buffy the Vampire Slayer' and 'Supernatural' universe. It has some really interesting plotlines where Xander uses his street - smart skills to deal with the supernatural threats in the 'Supernatural' world.