The two groups of Chaotic Believers in the manor were sorely unlucky; Malin and Ails—two Legendary Casters—created a Spell Formation that turned the three-and-a-half-story building where they were into ruins, and eventually, it was only through the scattered trinkets on a number of corpses that Casaman could deduce that these were members of the cult he once belonged to.
In other words, it was them who summoned Good Fortune Sir, but as for the person who came to kill them and ultimately perished in the fire with them, their identity remained unconfirmed.
