Hallow Keepers are people who, at a young age or in the womb, were “touched” by a Hallow, meaning that they, or their pregnant parent, had a close encounter with a Hallow which resulted in it being absorbed into the child, allowing them to “externalize” their soul into a physical weapon with unbelievable power. However, contradictory to common belief, this is not the only way Hallow Keepers can be born. The other way is if two Hallow Keepers have a child, without a doubt, that child will be a Hallow Keeper, but due to the turn over rate of Hallow Keepers, this is not a well used method.
The Shadowmen Order was created by Hallow Keepers as an organization to eradicate Hallow Incursions, originally done by sending individual operatives on missions, but the success rate was low, and so eventually, the Order began sending Operatives (Hallow Keepers) on missions in pairs with an Informer, someone without the ability to “externalize” but who had a close encounter with a Hallow yet didn’t, for some reason or other, absorb the Hallow into their soul.
Frequently, a young Hallow Keeper will often experience that their externalized soul melds into their body until their soul has matured.