User blog comment:FairyRaven/Fairy Tail Chapters 338, 339, 340: Review and Commentary/@comment-77.194.131.168-20130705134541/@comment-7418318-20130705181332

Since the Arcadios spy was just an early concept that seems to have gotten scrapped, you can hardly call it that.

Maybe the little bugger was originally supposed to be Arcadio's spy but was switched over to Zeref.