Given Allister's love for Ghost - type Pokemon which are often associated with the unknown and mystery, and Bea's focus on Fighting - type Pokemon which represent strength and directness, their personalities could clash at first. However, as they get to know each other through their shared love for Pokemon, they would find common ground. Allister might share his insights about the more ethereal aspects of Pokemon battles, and Bea could show Allister how to be more confident in the physical aspects of battling, creating a harmonious relationship in the long run.
In some fanfictions, the theme of discovery is present. They might find a new type of Pokemon or a hidden power within their existing Pokemon. There could also be a theme of mystery, for example, if they encounter a strange phenomenon in the Pokemon world that they need to solve. And of course, the theme of loyalty between them and their Pokemon is often explored, showing how their Pokemon support them in different situations.
You can start by looking on fanfiction websites like Archive of Our Own (AO3). There are often a lot of Pokemon fanfictions there, and you can specifically search for ones involving Bea and Allister. Another option is FanFiction.net. Just use their search function and type in the relevant keywords.
Perhaps a story where Allister is having trouble with his confidence in battles, and Bea decides to train him. She shows him new fighting techniques for his Pokemon, and in return, Allister teaches her how to better understand the more mysterious aspects of Pokemon battles. This way, they both grow as trainers and form a strong friendship that helps them face tougher opponents in the future.
One common theme might be self - discovery. As they interact, Mae and Bea could learn more about themselves. Also, family dynamics could play a role. For instance, how their families influence their relationship or how they create a new 'family' of sorts with each other. In some fanfics, there could also be a theme of overcoming obstacles, whether they are external like a villain or internal like personal insecurities.
I don't know exactly who Bea Munoz is in this story as I haven't read it. But she is likely the central character around which the ghost story revolves.
The plot could be that Bea discovers Luci has a secret power. She initially fears it but then realizes it can be used for good. They decide to keep it a secret from the rest of the kingdom as they explore how to use this power to help the people without causing panic. For instance, Luci's power could be related to communicating with the spirits of the forest, and they use this to find a cure for a mysterious illness spreading in the kingdom.
I'm not sure about specific 'mae x bea fanfic' stories offhand. You could try searching on fanfiction websites like Archive of Our Own. There are often many user - created stories for various pairings, and you might find some great 'mae x bea' ones there.
A well - crafted plot involving Allister's Pokemon battles is also appealing. For instance, if the battles are described in great detail, with the use of different Pokemon moves and strategies, it can be very engaging. It could also include unexpected twists in the battles, like a new move his Pokemon learns at a crucial moment.