Na Ppaego Da Gwihwanja

Average college student Il-Han Yu has always gone through life without being noticed by anyone, even God! So when monsters were about to invade Earth and God sent all humans to other dimensions to train with mana... he forgot Il-Han and left him on Earth for 1,000 years! Realizing his mistake, God sends the straggler two angels to assist him as he takes on the monsters, eventually turning him into an unstoppable force. Now that people have returned to Earth, will Il-Han finally be seen?

(Source: Tapas, edited)