Going a bit scientifically, in cosmology Vortex is used as a second name of Black Hole (Don't argue with me; I'm into astrophysics like no one else), thus Black Hole related things being just Vortex things. Vortex is ranged, so this theme is now occupied. Also, Vortex is in the center of the Quasar, so, you know... It wouldn't be really original.
Well, it is a split off of the range class anyway.
I'm just going to say one thing: nebula and stardust are the same. Nebulas form stars. Nebulas are made of stardust.
This would actually even further that, as summoner was a split off magic