The Last Resurrection

After getting the power of immortality from dragon blood, the Kaigen Ryujin became a shura- where a person is consumed by the joy of killing, losing their humanity to become a "demon of carnage" Every time he died history reshapes itself to keep him alive. The only thing that can kill an immortal is Eternis Severance blade. Wolf -Kaigen Ryujin's adopted son used that blade in order to kill his father.