Sigmar's Anvils

Among the many fanatics who purport to understand the true nature of Sigmar, there are those who shoulder the burden of wickedness that the Empire allows to flourish. They believe that each Mutant born, each calamity, each new incursion, each war is just another sign of Sigmar’s displeasure. Having witnessed the results of these conflicts, the tattered lives of those who survive these atrocities, they can no longer tolerate the horror of the world, and they commit themselves to purifying it. 1a

Sigmar’s Anvils is a freakish collection of fanatics who put themselves through awful trials in a desperate attempt to redirect Sigmar’s wrath from the innocents to themselves. Much of their time is spent finding new ways to cause themselves pain, but pain without killing themselves. Most Anvils scourge themselves and pack the wounds with salt, whilst others may cut ribbons of skin from their flesh and dust the bleeding rents with ground glass, sand, or in some cases lime. They subject themselves to fire, beatings, and just about any other horrific act they can to ensure the Empire remains safely under the protective hand of their chosen God.

Generally, the Anvils collect in small groups of a dozen men and women. They rarely remain in one place for long since locals can scarcely tolerate the sounds of their cries and moans. But really, they move to make certain the blisters on their feet are fresh and weeping. These groups never take the easy routes; they travel through the wilderness and never on roads or paths, but rather seek out areas rich with thorns and brambles to ensure their flesh is torn and oozing. Unsurprisingly, the Anvils are few in numbers.

Source
pg. 107
 * Warhammer Fantasy RPG 2nd ED -- Tome of Salvation

pg. 108