User blog comment:Carebearheart/Female Dragon Slayers/@comment-25991520-20150131061448/@comment-9595671-20150202132618

While the number Seven in important I think we've noticed so is the number 3

Fairy Tail has 3 generation 1 Slayers, there always seems to only be 3 of there S-Class wizards present at one time, I can't recall anymore 3 examples though but I think there's one or two more.

And actually that rule of 7 can possible still work if Mashima made it so 7 Guilds had Dragon Slayers, but after Ch 415 I kinda agree that we're not gonna see anymore slayers.

Kinda wish there were more, I would have wanted to see more Dragon Slayer elements.