User blog comment:StickFigure01/Heroes and other supporting characters that should've made an appearance in Arrowverse and Supergirlverse/@comment-27700324-20180104192651/@comment-27220799-20180105071217

I disagree.

1st: The Hawkman & Hawkgirl are Carter Hall & Kendra Saunders. Since Time Master Druce & Mon-El mentioned Thanagar in both their universes, I believe Katar Hol & Shayera Hol would be perfect in both universes.

2nd: In the comics, T.O.Morrow was a Flash villain as well as a Justice League villain. We could say that Morrow was a former scientist at S.T.A.R. Labs who  specializes in robotics, and that he was fired  before the particle accelerator explosion when he's work became erotic. That's when during 3 years he created Red Tornado to get revenge on S.T.A.R. Labs, But that's also when the android's programming evolved, became a hero & joined Team Flash.

3rd: If not Starfire, what about her doppelganger Power Girl/Kara Zor-L/Karen Starr? But definitely not as a villain, but as a hero.