The time-traveling girl stole the core of the world, returned to her original world, and abducted the Son of Destiny.
The world is going to end.
Tiandao found the strongest man in the world and persuaded him to go to the interstellar world next door that was about to be penetrated by aliens and snatch the core back.
Good news: She's really strong.
Bad news: He is a villain who has been training hard in the wilderness for hundreds of years and only wants to sharpen his sword and destroy the world.
Tiandao: Let's discuss it and go out to save the world.
Lan Xu: I remember that my setting was the villain.
Tiandao: Isn't this a coincidence? Let's go and destroy this world together first.