If he is
that powerful, like unto a god, why does he have to wait a thousand years for anything?
No plan survives contact with reality. A
thousand years is a long time to survive such contact. Stuff happens. Volcanoes explode. Earthquakes occur. Tarrasques wander through. Or... adventurers wander through. The world does not sit still for a thousand years for that plan to complete. Entropy is more powerful than any BBEG.
And, like, how are the PCs expected to deal with this crumbum if nobody in a thousand years has so much as nixed one of their plans? Asking a bit much, in terms of credulity, if you ask me.