Inspector of the Three Realms

After waking from a thousand-year dream, he discovers that he has become a special lifeform existing beyond the Three Realms! He then learns that he has been appointed inspector of the divine, immortal, and mortal realms, tasked with finding rare treasures, secret realms, and opportunities, as well as resolving disputes between planes.

"What? You, an immortal, are planning to invade the mortal realm? Sorry, you're under arrest!" "What? There's an unparalleled secret realm that no one can enter? Sorry, I can get in!"