Deltreizor was that demon who managed to beat Satan and aslaved him, after they had a fight that lasted a whole year. He was utterly evil, spending over 2000 years corrupting ppl and consuming their souls to become stronger. While being the new king of hell, he tormented and slaughtered many people just to gratify his lust for blood. Many were against him yet there were also many who sided with him, like Razikiel, who was promoted to an excellent position at his side. But, becuz evil is not meant to rule, Deltreizor was defeated. Kael, using the striker, stabbed him, setting free all the souls he had taken and also absorbing him into the dagger that disappeared right after. Good riddance o_O