Undefeated God of War

The young man who once lived on the streets and suffered so much from human kindness has now transformed into a dragon and returned to the city, vowing to protect that warmth. The wealthy family that once abandoned him? I'll trample you to pieces! The woman who once abandoned him? Let you regret it for the rest of your life! Does anyone think he is useless? Then let you understand how much power a person standing at the top of this world has! He is a useless son-in-law and also the god of war.