I dont know if this was already a thing, but apparently Vesta can sense the Quilava? Was that previously established?
Secondly, I would suggest having either Vesta or Jasmine attack the Gate and enter the Bell Tower. It appears that normally intelligent Pokemon, such as Ghosts/Legendaries/etc. become self aware during the Dreaming. And, since the Tower is supposedly home to Ho-oh and a passing place for the Legendary Trio of Johto, I'd say its worth checking out.