God Buster : Descendant

Long before mankind, Gods and Goddesses rule over the world and left after an incident that drove them away from Faernasia to a new world.
With technologies and immorality, one man decided to open a sacred gate that contains power beyond imagination and perform an assimilation that fuses both world into a new world.
5 years later, nearly half of humanity has turned into demi-god and were rejected by society because of their dangerous powers. Humanity were fragile, as the government castrate demi-god all over the world.
With the oppression hit harder day by day, a group of demi-god decided to make a change for the world so that demi-god and humanity may co-exist.

They are known as the God Buster.