A Universal System, but I Am Already a Super God

Invincible and Walking Around the World Without Hiding His Strength, He Is Decisive in Killing. Thank You All.

Is There a Book That Is Invincible, Serial Number 001, and Is a God?

I want to read a book similar to "I am invincible below the author, but I am invincible above the author."

Invincible! Cool! Relieve Your Anger! It's a Cool Story Where the Protagonist Doesn't Feel Aggrieved for Even a Second!

I want to read a book similar to "My Best Customer".