What Do You Get When You Mix a Genderless Entity And A Trans Teen?

A trans gangu/genderfluid cassian body sharing au
Gangu Gwon has struggled with being trans and gets bullied at school. He doesn't feel like he can talk to anyone about it . . . that is until one Cassian Lee gets shoved inside his body and they're forced to share in their problems.
can they learn to get along when one seems hellbent on beating people up and the other wants nothing but peace? Or will they remain just two ghosts haunting the same living corpse?