Hearing the title of the Strongest Ghost King, all three of them were rendered speechless. The possessor of that title is a deviant being who defied the Heavenly Will itself. Even though he had become the strongest being in their world he had also become the only banished existence by the heavens.
He was imprisoned in his own palace. The heavenly will wouldn't let him out unless his desires were fulfilled. It was this desire that made him decide that he wouldn't leave the Mortal Realm. His reason is vague, he told the heavens that he is waiting for someone and he wouldn't leave unless that person had returned to his side.
