Ever since I saw Wisp's unveiling I have always thought it might be kind of cool if she had a helmet that made it look like she was wearing a witch hat. Now I know some of you are going to look at me and say, "You're Stupid! DE won't accept that! They don't like helmets that look like hats!" However let me direct you to Mesa's Falcon Tennogen Helmet, Limbo's Vistyxio Skin and Limbo's Graxx skin.
So I think it is very clear that DE will accept helmets with a hat like nature so long as it makes sense with the frame. Personally I feel that Wisp having a helmet that makes it look like she is wearing a witch hat is very fitting.
Anyway, I just threw this idea out there, because we all know that sooner or later DE is going to allow tennogen creators to make skins for her and now I have planted the seed that will hopefully inspire someone to make an awesome helmet for her. Enjoy.