The 73'th

When a man who uses his eloquent tounge and his smarts to advance into the foundations of society is summoned into a world of monsters and magic as the 'Hero', he is forced to fight against the bane of all living things, the 'Eater of Souls'.

After getting completely overpowered by his enemy he gets killed, and just when he thought his eternal sleep was finally at hand he is reincarnated into a new world as a demon lord.

This is the story of the 73'th, and weakest of the demon lords, the one-horned demon, Azazel.