User blog comment:Omega natsu2/Fairy Tail Episode 197: Hisui Rises, Review./@comment-24622358-20141108234441/@comment-207.160.210.133-20141109015438

No all Hisui said was it was because of the eclipse door which is the same as saying because she is Erza. I still don't get the whole Key thing because if the origianl Gold Keys don't work then why would these Keys work and why would you give them to non celestial spirit Mages and the Keys have no connection to the spirits what so ever. If you can't force close their gate with the original gold Keys I don't see why these Keys would be anymore useful. The idea behind the Keys is that it works as a 2 way system with both parties agreement. First their have to be a contract between a mage and the spirit for the Key to work because if the contract is null and void then the Key wouldn't work as seen this arc with the gold keys. At the same time Celestial spirits can only end thier contract if the user dies or agree like Lucy did the Tenrou arc. If the spirit could have ended their contract on thier own free will then Aries and Leo would have left Karen and ended the contract but the couldn't without Karen releasing them from the agreement from what I understand from the Loke arc.

The whole filler arc is a plot hole. To many things are happeneing that doesn't corrospond with the Manga.