Everyone Else is a Returnee

Web Novel Korean Translation “Everyone Else is a Returnee”
Description:
Left out during the elementary school picnic.
Left out during the middle school camp.
Left out during the high school trip.
I finally became a college student, and what? I’m left out from all of humanity?
Ignored by God, Yu IlHan spends a Millenium honing his skills, watching over the earth alone while everybody’s away in other worlds.
His legend starts after humanity comes back and meets the Great Cataclysm!