I Am the Nanny of the Villain - Chapter 7:

A World of Warcraft hunter player inexplicably entered the world of Azeroth in his sleep. Turned into a high elf ranger, and at the same time inherited the title of Baron Cheap Daddy (Baron Blood Eagle) who died.

But the tragic original history that Blizzard bestowed upon the blood elves made his hair stand on end. He doesn’t want to become a heartbroken person and doesn’t want to die, so he can only struggle desperately to change the original history.

- Description from novelbuddy

A 34-year-old NEET otaku, chased out from his house by his family, found that his life is reaching a dead end. He then recalled that his life could actually have been much better if he had made better choices in the past.

Just when he was at the point of regret, he saw a truck moving at fast speed, and three high schoolers in its path. Mustering all the strength he had, he tried to save them and ended getting run over by the truck, quickly ending his life.

The next time he opened his eyes, he is reincarnated to a world of sword and magic as Rudeus Greyrat. Born to a new world, a new life, Rudeus decided that, “This time, I’ll really live my life to the fullest with no regret!” Thus starts the journey of a man yearning to restart his life.

On this land of real souls, with millions of different martial art institutions, there’re so many strong fighters just like the trees in the forests.

A recurring nightmare afflicted Khan's nights since the Second Impact. His dreams replayed the scenes of the crash of the Nak's spaceship, an alien race that the humans had defeated five hundred years ago.