The Netherworld Empire's recruitment might seem beneficial, but it was actually assimilation—a complete eradication of a faction. Over time, these people would be scattered and integrated into the Netherworld Empire. This might not seem bad, but the Spirit Race had a long heritage and, more importantly, valued all the secrets of their race.
Once all the Spirit Race's secrets were taken, they would lose all their value. Whether they lived or died would be of no concern to the Empire.
In truth, recruitment itself wasn't terrifying. Joining a powerful empire had its benefits for any faction. The fear was joining an empire that was too domineering and ruthless—one that would take everything and then discard them like trash.
