Benjamin created his force, which was called the demon hunters organization. Benjamin recruited members from all over the world, it didn't matter how powerful he or she was as long as they shared the same goals which were to exterminate all the demons in the world, then they were free to join in.
When the demon hunters organization was first created, it was only a petty force that the others didn't even put into their eyes. Though they didn't respect the organization, they all recognized Benjamin as one of the finest experts in the world.
And it shocked the entire underground world when that little organization grew into an organization that was capable of contending against some platinum rank forces.
The reputation the demon hunters organization had in the underground world was exceptional, to the extent that they were even part of the forces which were verified by the big three.
