I think Ethan Hunt could be a great character to pair with August Walker. Their different moral compasses and methods would create a lot of interesting interactions and power struggles.
A character like Brandt could also be interesting. He's more of a behind - the - scenes type, and his intelligence and loyalty could either clash or complement August Walker's more brash and dangerous nature.
Ilsa Faust would also be a good choice. As a strong female character, she could match August Walker's intensity and there could be a lot of intrigue as they try to outwit each other or work together depending on the situation.
Bill Cipher is an obvious choice. Since they are both from the same 'universe' in Gravity Falls and seem to have some sort of connection already. Their interactions can create really interesting and often chaotic storylines.
I think a character like Leo would be great to pair with Ainsley. Leo is kind - hearted and adventurous, which can create interesting dynamics with Ainsley. Another good one could be Mia. She's smart and has a strong personality, and she and Ainsley could have some really engaging conversations and adventures together.
A more emotional plot idea could be August Walker falling in love, which would be very complex as his dangerous lifestyle and secrets would constantly be at odds with his feelings. This could lead to a lot of internal conflict and difficult decisions.
A new character could be paired with August. For example, a character who is from a completely different world, like a commoner who has no idea about the royal and upper - class drama. This would create a contrast and could lead to an interesting story of August learning new perspectives from this person and changing as a result.
Kuzco would be an obvious choice. Their relationship in the original story is full of conflict, and in fan fiction, they could have new adventures together. Maybe they are forced to team up against a greater evil and slowly start to understand each other better.
One common theme is redemption. Many fanfics try to give August Walker a chance at redemption after his actions in the movies. Another theme is exploration of his past, like what made him the person he is. And power struggle is also seen sometimes as he is a complex character with a lot of power.
Naoto could be a great character to pair with Chie in a fan fiction. Naoto's detective skills and Chie's combat abilities would make them a formidable team. They could work together to solve a complex mystery in Inaba that has both a physical and intellectual aspect. Additionally, Rise could be paired with Chie. Rise's idol status and Chie's martial artist identity could lead to some unique situations. For example, Rise could ask Chie to be her bodyguard during a concert tour, and they could end up facing some Shadows along the way.
Brian is a great character to pair with Stewie. Their dynamic in the show is already rich, and in fan fiction, it can be taken to new levels. They can have deep conversations or get into wild misadventures together.
Dipper is a great choice. Their personalities are quite different, with Dipper being the curious and nerdy type and Pacifica being the rich and initially snobbish girl. Their interactions can lead to a lot of interesting storylines, like when they first met at the party and there was that instant tension.
You could also check out Tumblr. There are often fanfic writers who post snippets or links to their full - length works about Jessica Jones and Trish Walker on their blogs. Just use the search function and look for relevant tags.