The Metalwood Saga / Reference Guide

Full-series spoilers

Soulshadow

Soulshadowing is a dark, necromantic Gift of the Soul utilized primarily by the shadowy Eglarian priests. It allows a mage to perform a ritual to "resurrect a freshly-killed body, making it a slave of the Twins". The resurrected victim becomes a "shadowslave"—a body that is only half-alive and entirely stripped of its free will. The Twins and their masters maintain absolute control over the shadowslave's "movements, their words, their deeds," creating an obedient, undead servant.