Prologue
There have always been demons. Sharp fangs, sharper claws, able to tear though stone and steel. Drawn to places of misery and violence to destroy and feed.
But from the dawn of time humanity has always had one defence against them.
The Soulblade.
Weapons which hold part of the users soul. They are the only thing a demon can't destroy. They are only thing that can kill them.
So mankind flourished. As the ages went by demons became less of a threat. But the soulblades, and those who wield them, have always been humanity's best defence.