He may be a fugitive demon king, but he is not weaker than he ought to be. In fact, the opposite is true, thanks to the crown of domination.
A demon king with a plane in the abyss and the support of the abyss will become a fugitive if they encounter him. They will pick up their things and run without any thought of relying on their plane for safety.
He is stronger than ever before because he sacrificed all his crowns to the crown of domination. He even sacrificed all the Authority of the Celestial Supreme that Legion had amassed to it.
Those were supposed to be sold for soul stones, but Legion doesn't need them anymore, so he could use them for power. And what a power it is! The crown of domination accepted everything powerful he could throw at it, regardless of its origin, and gave him power in return.
I've started a new book titled DESTINY GAMES. Please check it