I'm Learning to Save God in the Mysterious Realm

[No system + endless days + the protagonist is neither human nor ghost + ambiguous and it's over] Li An died on the third day after being sent to the Strange Realm. "I know you are dead, but don't die first!" The strange ghost doctor brought back Li An's mutilated body and stitched together several kinds of ghost limbs. "Resurrect and become an existence beyond humans and ghosts!" The ghost doctor pulled out his own heart with a grin and sewed it into Li An's body. From then on, the most mysterious, crazy and powerful ghost doctor in A Nightmare on Elm Street disappeared, and was replaced by an incredible ghost doctor!