|A man with his own group of bandits who collects all manner of demon blades and magic swords. Taking up one of these blades for personal use caused his intellect and rationality to decay at an alarming rate. Consequently he began leaving tracks in his destructive wake—tracks obvious enough for the Lumiel Order of Holy Knights to get ahold of.
Corwell was previously expelled from the Lumiel Order as a result of his grandfather's criminal actions. Depression set in shortly after, and he began to crave demon blades just as his grandfather had. While on a quest to gather as many of them as possible, he set his sights on the demon blade protected by Sevilbarra's lineage. That's when he came across Keralbarra's wedding procession and slaughtered everyone present.
The katana Sevilbarra carried that day was a ceremonial one. If only he had had the foresight to use the demon blade against Corwell, perhaps Keralbarra would still be alive today. But, alas, that did not come to pass.