I have this one zool x fire emblem AU....

Zool are a mercenary band created and lead by Ryou and Shirou, their origins, relationship or objectives are a mystery. I don't know their classes but Ryou does not see combat and Shirou is maybe a magic class

Torao is a cavalier and Minami a shaman/dark mage. Both are nobles who run away together and found themselves joining the merry band. Minami is kind of their strategist, but no one except Torao knows about his past and Torao at his request doesn't talk about it either. Torao is more open to talk about himself, but not in detail and he likes to change the story a lot so no one has a very clear picture

Touma is a mercenary and Haruka a thief. Haruka was orphaned at a young age and dedicated to thievery to survive, Touma was a wandering solo mercenary who met Haruka in a random town. Touma taught him a lot of stuff and so they started traveling and doing mercenary work together. They see each other as brothers, and Touma is the most important for Haruka since he was there for him when he had literally no one else. They eventually also joined the band

I have a bit more in mind that i don't have wrote down, but this is the AU idea more or less