The Belial's Brood is a dangerous group of kindred that few understand and even fewer have the interest in understanding. These Satan worshiping kindred openly breach the masquerade and cause death and destruction were ever the good. Thankfully they are incredibly rare and cells are dealt with quickly and with surprising efficiency. Nothing gets squabbling kindred to put aside their differences than the chance to kill other more dangerous kindred after all.
How to get into the Belial's Brood is really anyone's guess at this point as little information about them is kept and they are in fact rare. These renegades and anarchists and never tolerated for long and never excepted for in a court. Most Kindred have a hard time even believing them to be more than a tiny cult and for the most part, they're not.
The Invictus: "Great... more rebels."
The Lancae Sanctum: "Blasphemers to the highest level. They all should be crushed with force in god's name."
The Ordo Dracul: "Huge interruptions to our delicate work. Their 'miracles' are shams that waste of time and effort."
The Circle of the Crone: "Making us non-Christians look bad. Monsters that have no control."
The Carthian Movement: "The biggest threat to both the mortal and kindred civic structures that threaten to destabilize everything."
The Unaligned: "I would find you guys cool if I were into rape, murder, and lighting things on fire... I guess."