Yeah, something like that. A being of incredible power that rarely manages to pick a course of action for long enough to actually do anything meaningful, but when it does, all you can do is stay out of its way until it changes its mind. Which probably won't be very long.
The Sepulcher of Knowledge is an area in Maldraxxus. Elune definitely isn't guarding it since she never shows up when we break in.
The Sepulcher Zovaal wants to go to is some other thing we don't know much outside of a name about.