I think it's pretty clear by now (or at least it should be) that Black Siren is not going to be a hero suiting up as the new Black Canary alongside Team Arrow. Dinah Drake is a fitting successor to the mantle that's ended with only arrows to the chest, and I hope she sticks around and actually gets some more to do. But what about Black Siren? Laurel fans are obviously a very vocal fanbase who want nothing more than to Katie Cassidy grace their television screens once more as either version of Laurel Lance. Now, Katie Cassidy is confirmed to appear in the finale of Legends, which typically jumpstarts the third season. So is Katie joining the Legends? Maybe. It's been floating around for a while now, they've mentioned they want to bring her back and her best friend (Caity Lotz) is the current star of the show. But the producers of Arrow have mentioned they still want to use her going into next season. But with so many new recruits on the team and a new Black Canary in the works, what's left for her to add?
If anyone has ever watched the Vampire Diaries (used to watch it with my girlfriend - it's actually really good), there was an evil(ish) doppelgänger character by the name of Katherine Pierce. She would basically roll into town every few episodes to either cause trouble, torment or assist. She did what ever she had to do to survive. And all that reminded me of Black Sirens obvious self-preservation traits. She helped out what ever side she thought would be winning (assisting Team Arrow and then helping Prometheus so he didn't kill her). She was sarcastic and all around fun, a fan favorite. She never stayed for too long and her loyalties were always thrown into question. Between her love for Stefan and her hatred for the good and pure Elena, she would go from dotting seductress to psycho killer, something that perfectly fits with Black Siren. She obviously still has remaining feelings for Oliver, and a distinct dislike for Felicity.
With Katie's obvious love for the character, having her float around every few episodes in a way that constantly questions the effects on the Team, it would be a great way to not only delve deeper into Siren's character but also please the Laurel fans and bring those who have left back into the fandom. Shown this week by having Malcolm Merlyn appear in three episodes, Katie could be a part of the Legends (there's a rumor Sara brings her back with the Spear) and an occasional friend or foe for Arrow.