Yes, she will become part of the harem, so we must ready our body for the first 3P with the sisters. Of course, there will be even 5P and later 6P and 7P too, but the first 3P with the sisters is always the most memorable.
@gaigous Keyaru doesn't have the mighty reader's power to see everything at once. He knows Norn is evil, but he has no proof in this life. Keyaru might be completely broken, but he does abide by his specific principle to not take revenge unless evil has been done to him in this life.
He's psycho and he's completely inflexible to this rule, much like psychos are.
She can kill her cause .... he's a lolicon at hearth and wouldn't wanna hurt the cute ... well somewhat cute loli princess norn?
(minus the crazy masochistic parts)