Started Saving the World at the Age of 18

18 Years old is the time of youth, The age when you should be enjoying your youth, But because I can travel through hundreds of years, Knowing the end a hundred years from now, The timid young man gradually awakens, Limited life should be fought hard, Let's see, How do ordinary young people grow up? Save the world step by step! The introduction is too weak, please move to the main text. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.