Han Fei had a thorough conversation with Spider, and he knew that once Butterfly targeted someone, it would start by destroying the target's spirit. Butterfly excelled at using psychological suggestions and dreams.
Whether there were ghosts in the world, Han Fei did not know, but he knew Butterfly was constantly trying to make him believe in ghosts and instill a fear of them.
The Meat Factory Courtyard, where Spider had lived, was filled with shrines. The elderly residents who had not moved out were firmly convinced of the existence of ghosts and gods, likely a masterpiece of Butterfly.
In order to deal with Spider, Butterfly would even create a terrifying atmosphere throughout the entire building.
In Butterfly's eyes, all people were exploitable, and human nature and hearts were merely toys in its hands.
When Han Fei exited the game and began thinking about Butterfly involuntarily, it indicated that Butterfly had already made its move on him.