Owari no seraph : The switch

Owari no Seraph :The prologue introduces what happened to the world four years ago, when a mysterious virus brought the world to a sudden end, where only children survived and enslaved by vampires .Yūichirō Hyakuya and Mikaela Hyakuya, who are among the group of orphanage children in the underground city of Sanguinem, the vampire third capital. And as some of you know the story on how the two had separated ,Mika turned to a vampire (spoiler for those who haven't watched) and Yuu who fled and found himself in the Japanese Imperial army .But what happen if they switched positions ,Mika in the imperial army and Yuu the vampire >:) .... Note : I do not own owari no seraph or the characters , just the fan fiction itself :) This would be my first time writing a story so please do mind my mistakes I make in the story .

Edit :I'm not an expert in writing (majority of them were written at 2am)so there's probably some grammar and spelling issues I've missed .So if there're any error you find ,please notify me so I can make the changes :) Hope you enjoy the story ,I really appreciate it .