Sisters of the Golden Erinyes
The women of this monastic order are trained in the ancient fighting art or Hamatulatsu. They are able to use their unarmed attacks as a substitute for any melee weapon and mimic the abilities of bearded devils as they perfect their style.
Men in the order become either Hellknights or priests to Asmodeus, but the women become apt warriors, scouts, assassins, and protectors. Monks benefit from this prestige class the most, but fighters trained in unarmed combat as well as the occasional druid find this career path to be rewarding. Rogues and bards are not allowed in the order, nor are arcanists as either their mindset or their focus on other activities do not go well within the order. Paladins never join without losing their abilities first and changing to non-good alignment.
The style of this order focuses on cycling through damage types with unarmed attacks, and have some surprising techniques, increasing their range and gaining supernatural effects that are added to their attacks. Those that reach the pinnacle of their training gain an Erinyes as companion, and ultimately end up in the Nine Hells as Erinyes themselves, should they die in combat and not return to life.
Sources: Pathfinder Chronicles Campaign Setting, Own Stuff