Harley Quinn appeared in a small cameo role in Arrow's second season, but never appeared again. Most assumed the reasons behind this involved the fact that Harley Quinn is too big a character and too heavily tied to Batman. Many also assumed that the fact that there was a Suicide Squad film coming out that she didn't appear again because the movies were using her. This is most definitely the case, but what would her role have been if she'd stayed on Arrow?
Again, most people would assume this role would be in the Suicide Squad, but I think otherwise. I believe Harley Quinn would have played a villainous role (maybe even the first villainous role) to Willa Holland's Thea Queen/Speedy. When writers are planning out storylines for actors, they will consult the actors involved mainly and deal with the others later. In a recent interview, Willa Holland said this:
“We had big plans for Harley. But, I guess something came down from DC execs that told us to shut it down. I mean we had that tease with the pigtails and the ARGUS outfit but, we’ll never see it. We would love to Harley in Arrow but it will never happen.”
This would suggest that Thea had a part to play in Harley Quinn's story on Arrow. Was she going to end up being good friends with Harley, having a sort of Harley Quinn-Poison Ivy friendship? Or maybe Harley Quinn was meant to be the first big challenging villain for Speedy to face to earn her position as a hero of Starling, much like how Black Canary had Brick.
So what do you think? Was Harley meant to help progress Speedy into a fully-fledged hero? Do you think Harley will be back after the Suicide Squad film comes out?