Arrow Season 5 Finale: Ranking The Probability Of 17 Major Character Deaths In 'Lian Yu'
16. Black Siren
Black Siren, who hails from Earth-2, is a means of keeping Katie Cassidy in the Arrowverse after Laurel Lance's death. Even better, though, is the fact that it gives Cassidy the chance to have a lot of fun and display her powers in ways too often not offorded to her as Laurel/Black Canary.
She'll be fighting alongside Prometheus in the season finale, which means she could feasibly become a fatality of what's likely to be a brutal clash. However, Cassidy has been confirmed as a series regular for Season 6, and while that could just be misdirection, it seems more likely she will be sticking around.
There's still plenty of the Black Siren character to explore, whether that's as a villain or a potential face-turn, and it's hard to see the writers killing off another character played by Cassidy.