User blog comment:BlueSaga/Final Fantasy X Fire Emblem/@comment-4743273-20140215043546

No way should this be a fighting game. I've been thinking about this crossover too, and I think that it would be best if strategic movements around a battlefield were used Fire Emblem style, but instead of just having two characters fight in a cutscene, an encounter would be fought turn-based in the style of FF. Characters and enemies could also team up into groups of 2-4, making strategic teams important to take down multiple enemies, or powerful enemies.

As far as characters, though, I'd say the main protagonists should be popular characters from each franchise, like Cloud, Marth, Ike, Squall, Chrom, maybe even Lightning. Although, the crossover has to be somewhat believable.