Talk:Light Novel Volume 19/@comment-34937324-20180717184325/@comment-24859003-20180718104347

Well one theory could be that her sister was responsible for the destruction of the world and that S'yne's sister has a soul fragment from Medea like Malty has.

Another possibility is that she is also a vassal weapon wielder and that like S'yne she also wasn't in her world when it was destroyed.

Everything is speculation and we have to wait for the latter volumes to confirm that though.