Kami-goroshi no Maou, Saijaku Shuzoku ni Tensei Shi Shijou Saikyou ni Naru

Hiram, the strongest demon king in history and ruler of all demons, defies the Demon God’s demands for sacrifices. This defiance leads to a fierce battle that leaves Hiram dead. Despite being the strongest, he could not overcome the truth of this world: Demons cannot defeat the Demon God. Five hundred years later, Hiram has finally reincarnated as a human. While humans are considered the weakest race, they actually have the highest potential for growth—and Hiram fully intends to take advantage of that fact. So begins Hiram’s new quest to kill the Demon God in this unique adventure story! Source: Manga UP! Global --- The strongest demon king in history returns from the dead and embarks on a grand adventure to find the god of all demons…and kill him! After centuries of war between demons, the world was finally united under the overwhelming power of Hiram, the strongest demon king in history. No demon could match him, but even the mightiest king can not so easily defeat a god. When Hiram defied the demon god, he and the deity engaged in days of fierce battle where, in the end, he was cut down by divine punishment. The demon king, however, is never without contingencies! Hiram cast a spell that, in the event of his death, would reincarnate him years later with all his powers intact. Only this time, he would be born as a human, a race the demon god has no power over! With his life restored, Hiram begins a grand adventure to find the demon god and kill him once and for all! Source: SQUARE ENIX USA, Vol. 1