How did Diablo get the body body double?

Worm arrow inserted into arm. Through the inquiry, I know that the role comes from the online novel About My Reincarnation as slime. In this game, you have to get the worm arrow in Diablo's hand, and then you must be Dior, and Brando is Dior Brando after vampires. Then, insert the worm arrow into your palm. Then you will feel that your spirit has improved a lot and your knowledge has improved a lot. You get the physical double world that stops. So you can play with Dior's figure, body double.