Board Thread:Naruto Discussions/@comment-29378291-20160802051140/@comment-25122992-20160804101521

We don't actually know how superior the Rinne Sharingan's insight is to the one of regular Sharingan, but since it was said that Rinne Sharingan possesses all the abilities of the Sharingan, we can assume that their insight ability is pretty the same. At the same time, Izanami was designed specifically against Sharingan users, hence it affects not only the vision (something Sharingan users can easily counter), but the remaining human senses as well.

However, I also have some doubts regarding Izanami success on a person with god complex, although I have another thoughts on that matter: Kaguya was once said to be truly kind and caring person, which should be identified as her "true self", and Izanami is actually all about "accepting" it. Since her godlike personality came later as the result of her getting too much power only for herself, it can't be called her "true self", so Izanami could probably work on her.