The light and shadow inversion plan was inspired by the Shadow Thief from the Shadow Master Guild.
Using the Complete Resurrection Spell to revive True Wraiths, letting them enter a state of light and shadow inversion. Their situation aligns with the Evil God rituals, healing magic will cause them harm, while negative energy impact will heal them.
The greatest benefit of doing this is allowing True Wraiths to freely move outside the Weizemay Manor. There exists an intricate connection between both parties, making it impossible to completely escape the control of Shadow Manor.
Now there's an addition, to bear the Undead Divine Grace.
Ordinary people cannot bear this Divine Grace. The undead divine power contained within is even more terrifying than simple negative energy, turning them into undead, unless they are already negative energy creatures or have completed negative energy energization through the professional system (Evil God Rituals).
