the question stands above. Both nazar and black magic base on another power other than Allah's, so why is it not considered as shirk? In fact, Islam even tells to be careful about it, especially black magic. For example, why would i be able to curse somebody? Or how is it permissable that i can make nazar on somebody so that he will actually end up failing? We shouldn't be able to do that, because there's no other power than Allah.
Please no assumptions, but only answers from people who know for sure what the reason is. Allahu alem.