User blog comment:Relikz/Chapter 364: Tartarus Arc, Part 1: Immorality and Sinners, Review./@comment-8153438-20131220124934/@comment-7418318-20131220133038

Just because Yukino doesn't know about any other Celestial Spirit Mages doesn't mean there are none.

It can just as well mean that any other Celestial Spirit Mages out there are either keeping a low profile or are active outside of Fiore.... or that Yukino is really lousy at gathering intelligence.