Can I go to my world now?

Xin Zeling, A Genius who doesn't believe in Reincarnation, is in his fourth year in high school who accidentally went into another world where cultivation and monsters exist. When he opened his eyes a fluffy speaking dog was looking at him and said "Oh you're awake." Xin Zeling didn't know that this talking dog was a very strong being named 'Asther' that had took his soul to another world and it turns out that he will not bring him back until he had finished his task. "But I only want to go back!" He said. "Then you're gonna have to kill a certain person before that happens~"