Rilian is like the anti-Miranda. While Miranda is basically a lazy method to resolve a plot via killing/banishing villains, Rilian is a lazy method to kickstart a plot since he's the one stuck telling everyone what to do to avert disaster. One big difference is that Rilian is actually interesting, since he doesn't just rely on uber-magic power. It also helps that he's detached enough from the cast that he puts the tasks they need to do over their personal angst.

It's kind of jarring that Miranda doesn't seem to be aware that one of her colleagues is running amok after centuries of doing nothing. It's never a good sign when an incredibly powerful but passive entity suddenly stops being passive.