I think she's either his sister from a alternative universe/reincarnated and he just put her soul in his sister dead body. Or she's created by dark magic and he just got a random soul. But I doubt they are actual siblings, it is always adopted or fake ones in those stories
I think she's either his sister from a alternative universe/reincarnated and he just put her soul in his sister dead body. Or she's created by dark magic and he just got a random soul. But I doubt they are actual siblings, it is always adopted or fake ones in those stories