Divinity Attack? Huh?
It's probably just a Light-Attribute magic. The MC probably doesn't have such a thing...since the author didn't realise divulge their skills and only displaying skills as the story goes.
Dunno why but I was bored reading the melodrama between the sisters. I usually like those kinds of things but I don't even have a fond of the little sister that much, then they gave something like that? If they made the story inside their temple a bit more, I could like the imouto but ¯\(ツ)/¯ it was just too fast that I feel like it's too unnatural to be on that point of time.