Introducing other heroes

I'm hopeful that in Season 4 and S2 of Flash that we can be introduced to more heroes and villains from the comic books. Ideally it would be more similar to the Huntress type of intro (as in, not blatantly for a spin off).

I'm not sure about whether the trinity exists in the universe, but one idea I had for introducing them was to use alternate versions from the ones found in the DC Films. For example, instead of using Diana as WW, use Nubia.