The Black Rock group are a group of summoners/magicians that use most basic mana based magic using pentagrams.
The group is made up of a bald guy with a pentagram eyepatch. Two other members of the group is Litnell and Kim Jin Woo.
The group seems to have magic that revolves around the use of pentagram magic. Every thing to their mana attacks to their fusion magic involves the use of pentagrams.
The group also utilizes numbers to increase their strength by ampliyingg their magic by combining it.
Fused Golem: When the group fuses with a Jumble Mumble Golem they increase its power and enlarges it.