The Strongest Magician in the Demon Lord’s Army Was a Human

In the world of demons where you can see every kind of demon and dark magical power evils. Mauo Army has a magician who has unbelievable magical skills. He can even destroy a whole army of demons with his magical powers all alone. He has a secret that he won’t let anyone know he is a human in the demon world that has that kinda of great magical powers. To hide this secret from others he used modern magical knowledge.