It's like, he knows so much about what could happen, what it is, and how to create one, isn't that strange? I don't think the King knew about what it actually was like the Queen and just fullying a purpose told to them. He can even go to the other worlds meaning he's not really from the Dark worlds, the same way he could even go to the real world, is so strange, also! He's not actually a Lightner since the Queen didn't know he existed, he could not even be one and is lying to us, maybe?! How does he know so much? Like, is there a book about it or he was the first one to discover about the fountain, and something similar had happened before so he stays to protect those worlds?? Can you imagine he's actually very old like a thousand years living in worlds like these??
I really want to read people theories and opinions about this, if you want please leave some thoughts!