Board Thread:Legitimate Canon Questions/@comment-26742635-20150721085855/@comment-4091815-20150722183542

Johnny Warren wrote: Cause the only abilities showed by Druids is the knowledge of the supernatural universe and how to use magical properties of herbs and rocks, while Banshee have active powers. Banshee are different from the were-wathever, the Shapeshifters, but cannot be classified as humans. Melissa is a human, not Lydia. I agree with Mgc, the reason why Mountain ash is inefficace with them is because they're immune to most of the supernatural things that are lethal to human and shifters alike

You can agree with whomever you wish but the canon is clear at this point.

Nothing Supernatural can cross a mountain ash barrier.

Banshee can cross and handle mountain ash.

Banshee are not supernatural as that word is defined by the show.