The Knight of Desolation.(DxD)

Draven was once known as the Knight of Desolation. He fought against the invading Abyss for over 10 centuries. He in the end fell when he fought the Abyss King who was invading his world. At death's door, the two dying beings came to an agreement as neither wished to die. With both of their power, they came back from death. Ony Draven was a girl and the Abyss King was a dog. What the fuck was going on?