Highschool DxD: Godslayers (Despair arc)

In a world of a supernatural there are many races demons, angels, fallen angels, youkais, dragons, vampires, gods and many more.

However humanity were at bottem of the power scale since supernatural beings considered them a weakling until 7 clan of humans got the power of a death itself. The supernaturals named them "The Godslayer" or common known as "Grimm" since they were considered descendent of Death itself. How they got this power no one knows. Because of this Grimms the descendant of Death were almost wiped out of existence leaving only few survivors left to scatter around world hiding their powers.

Anuka Kanno, That's the name of the boy who had lost everything. He lost everyone, found somenone and lost him too. The only thing that protects him from insanity is Revenge.