Evolving into an SSS-ranked Demonic Celestial

It's been two hundred years after the first war between the demons and the celestials. While the fragile treaty stood as a form of peace, both sides knew that it was only a matter of time before they clashed again. Amidst the chaos was Dean, a young demon who was unfortunate to be born with an incomplete demonic core. This made his life worthless, meaningless, and overall, useless. He was constantly pushed around and outcast, even by his own family... That was until he came across a pool of celestial energy that mysteriously made its way into the demonic realm. The energy got absorbed into his body, a phenomenon that was said to be impossible. This ordeal changed the course of Dean's life drastically, because he was no longer a complete demon due to the presence of the celestial energy... He became the first demonic celestial. And alas, when the final war between both races commenced, Dean was faced with the impossible choice of either protecting the demons, or eradicating the other side of his nature. Will Dean protect the same people that had always looked down on him? Or will he join forces with the opposing race, letting them suffer at the hands of the brutal celestials?