“Two non-existent things cannot intersect each other, just as something that exists cannot be omitted by something else that also exists. There is always an exception that links to an impossible. That exception is Hoku. Although we cannot meddle with each other's astralines, Hoku can because he is the exception to our limits. The fact that he hasn't died in the present gives us a dire opportunity.”
-The Covenant Of Timeless Mysteries”