Find the name of a fantasy novel

I forgot the name of the main character, but I remember that he had a master in the middle of the story. His master's name was Bi something (three words). He was very awesome. He was some kind of Demon Suppressing Envoy or something. He was basically the master of the strongest Boss. He lived on an island in the middle of a forbidden area. He had a mirror-like magic treasure that could monitor the entire forbidden area. It was a rather famous novel. Thank you!
When did I forget? I was a little confused. I just remembered that the book was quite long. The master of the main character was very awesome. He defeated dozens of powerful people by himself and lived in a place called the Hundred Thousand Mountains or something. The first place where their sect practiced was the Ghost King. Later, the Ghost King was killed by his master in one move. The Ghost King's wife became the new Ghost King. There was also an old man who refined weapons. He had a mount that only ate a kind of fruit and forgot about it. Anyway, his memory was fragmented.

Answer 1

I can't directly provide the name of the fantasy novel. However, according to my knowledge of online literature, the names of some fantasy novels may contain the following elements:

- magic
- mythical creatures
- evil person
- vampire
- take pills of immortality and cultivate oneself to become an immortal
- quarrel just to vent one's spleen
- a magic weapon

For example, one of the possible titles was " The Legend of Magical Immortals " or " The Divine Beast Frenzy ".