Regno Borealis, a medieval world recently emerged from the warp, teems with Monsters transported to the planet by arcane means. Inquisition teams suspect that an alignment of certain planets and stars opens ancient webway portals allowing beings and monsters to translate onto the planet.

The so-called Witchers are genetically enhanced humans created to fight the beasts with Sword and Bow. Swords enhanced with silver alloy reportedly deal more damage than steel. Inquisitors have detected no warp taint or heresy amongst these professional monster slayers. Indeed, some suspect that these slayers are akin to the Astartes and that the methodoloy may be a debased form of transmutation. As the original adepts passed, their successors may have had to make do with the materials on hand to create superhuman champions to protect the mundane humans wishing only to live in peace.