With so many interesting concepts and entities introduced to us in all the various seasons of Arrow/Flash/Constantine/LOT/Vixen/Supergirl, what are a few of the more mysterious forces that people would like to find out more about?

Personally, I would want to see more of the Speed Force, and if something like the Black Flash exists (Which is essentially the aspect of Death for the Speed Force/Speedsters) I would be veeeery interested in more aspects to it.

Vixen or maybe LOT would have to deal with some of the more mystical forces, and the concept of Time Pirates being fleshed out more would be appreciated.

For Supergirl...............................................I want the show to introduce something that interests me (don't hurt me I don't watch that show)

Giving us a true hint about heroes like Green Lantern would be fantastic at the very least.

What are some things that you guys want to see introduced or fleshed out?