Although Vaan knew spirits were sentient beings, he had dismissed the Death Eaters as being under the same category. As such, he was quite surprised to hear the Divine Lord Death Eater speak, even more so in the human tongue fluently.
However, his surprise was understandable. Anyone else in his shoes would have reacted the same way.
After all, the other Death Eaters were all Rank 6 or Rank 7 spirit beings. These existences were much higher than his presently contracted spirits, and yet they seemed even to be even less sentient.
No, it was more accurate to say that they were non-sentient.
Unlike the Divine Lord Death Eater, who had proven to be highly intelligent, the rest of the Death Eaters did not seem to possess any spiritual wisdom or wills of their own. Their mindless movements showed their lack of thought.
As such, it was easy for any observant person to determine the Death Eaters were different from other spirit beings.
