Help findin a manga from a bit ago

[sventle]

Gosh i dont remember much cept it was about some siblings. The brother was large and scary lookin and everyone thought he was a demon and the sister looked just like a normal person.
I think they lived in some church and at some point a priest trys to kill the brother but instead shoots the sister who was protecting him and it turned out she was the demon in the family.

Anyone got an inkling on what this might be?

 

[contrasena]

Well... Not exactly as you describe it but maybe "Shoujo Gensou Necrophilia "?

 

[Jonnzjonn]

This seems to be it?
https://mangadex.org/title/21670/freaks