User blog comment:SuBash/Questions/@comment-3061966-20130726212438/@comment-3061966-20130726235109

Well, for pre-existing fanon guilds, you would need to ask the creator.

Technically, you can make your own version of pretty much any Dragonslayer element -- that goes for canon and non-canon (single element or dual element). For example, Sky Dragon Slayer Magic (SuBash). We abolished the "first come, first serve" rule a while ago. However, your first character cannot be a Dragonslayer or any sort of slayer. For that business, speak with Perchan in the future, that's her area.

That would be wise since you're new. Normally, you only need to speak to her about Lost magic or Dragonslayer magic though. That's about it.