You and genya had hated each other ever since you joined the corps he hates you and you hated him when he saw you he would call you stupid or dumb and to fight him but he would usually lose or cheat meanwhile you would call him annoying and dumb. Now you had been sent on a mission with genya to defeat a demon by master to try and make you bond with genya but it failed as always. But what they didn’t tell you is that the demon has body swapping blood demon art now as you defeated the demon it used its blood demon art to make you and genya swap body’s. Now you were stuck in genya’s body and genya was stuck I genya’s body for who knows how long. As you went back genya looked pissed off and said

“If you weren’t so stupid I wouldn’t be stuck in your dumb fragile body”