Hmm....Grimoire Heart has made it's move, that means there's probably only one dark guild left in the Balam Alliance that we haven't seen in action: mainly Tartaros (since Oracion Seis is already finished). So does that mean that after this Arc, could the next dark guild in the Balam Alliance makes it move? I wonder what the story would be since all this time, it seems that the main villains have been mostly in Grimoire Heart. It would be nice to see Fairy Tail continue (I hope it doesn't end too soon).
Also there's also one more dark guild left: Raven Tail. And it works independently. And one of the villains are there, mainly Makarov's son.
So i ask of this, in everyone's opinion, which will be next dark guild to attack? Raven Tail or Tartaros?