User blog comment:FairyRaven/Fairy Tail Chapter 470: Hybrid Theory, Review and Commentary/@comment-7418318-20160125204101/@comment-7418318-20160126195420

I think he was fascinated due to the magic being so very rare or maybe having some dire consequences (like having to become a Vampire to get it), not because it was so powerful to actually impress him.

He was looking at it as if it was a rare specimen and not as a threat.