The main characters are Striker and Moxxie. Striker might be seen as the more dominant and aggressive one. He has his own goals and ways of doing things in Hell. Moxxie, who is associated with I.M.P., has his own set of friends and a life that gets intertwined with Striker's in the fanfic, creating a lot of interesting interactions and storylines.
You can start by looking on popular fanfic websites like Archive of Our Own (AO3). It has a large collection of fanfics from various fandoms, and you're likely to find quite a few 'Moxxie x Striker' ones there.
One popular 'Moxxie x Striker' fanfic is 'The Unlikely Bond'. It delves into a scenario where they are forced to work together on a mission and gradually develop an understanding of each other.
One possible interesting plot could be Striker and Moxxie being forced to work together on a dangerous mission. They start off hating each other but gradually come to respect one another's skills as they face various challenges.
Another theme is the contrast between their personalities. Moxxie is more reserved and proper while Loona is brash and moody. Fanfics play with this difference, showing how they either clash because of it or find a way to complement each other. For example, in some fanfics, Moxxie's calmness helps soothe Loona's temper, and Loona's boldness encourages Moxxie to be more adventurous.
One great 'Helluva Boss Moxxie x Loona' fanfic is 'Unexpected Bonds' on FanFiction.net. It really delves into their relationship in a unique way, exploring how they interact outside of work situations and gradually develop a deeper connection.
In a fanfic, Moxxie's accent could be a central part of a romantic storyline. Suppose there's a character who is initially put off by her accent but then gradually falls in love with her as they get to know her better. Her accent becomes something endearing and special, and they have cute exchanges where he tries to imitate her accent playfully.
A good one often has well - developed characters. Since Crimson Chin and Catman are both unique characters, it should capture their personalities accurately. For example, Crimson Chin's heroic and somewhat goofy nature and Catman's more mysterious and cat - like traits.
It can be depicted through her dialogue. For example, using specific words or phrases that are characteristic of her accent. Like she might say 'ain't' instead of 'isn't' or use some unique local slang.
You can try searching on popular fanfiction websites like Archive of Our Own (AO3) or FanFiction.net. They usually have a wide range of fanfictions, and there's a good chance you'll find Crimson Chin x Catman fanfictions there.