The original idea of Legends of Tomorrow featuring a revolving roster of DC heroes is becoming more of a reality, as both halves of Firestorm have now left the Waverider. While a number of the initial Legends are still on board, new blood is continually being added to the series. Season 3 already brought with it the addition of Zari before news arrived that Victor Garber, who plays Martin Stein, was leaving the show.The Crisis on Earth-X crossover gave Stein a much more dramatic exit than was previously imagined, but also heavily implied that Jax would stay aboard. There was even a funny nod to him gaining at least one of Spider-Man's powers to remain in the game. But the midseason finale of Legends of Tomorrow removed the second half of Firestorm and thus took the character's god-like powers out of play. The episode also hinted at some future Legends, and showrunner Marc Guggenheim has said Firestorm's replacement will be an existing Arrowverse hero.Related: Legends of Tomorrow to Replace Firestorm With Returning' CharacterGiven the expansive nature of the shared universe, everyone from Jesse Quick to Ragman to the Mari McCabe version of Vixen could fill that slot. And with career criminals like Captain Cold and Heatwave part of the original team, there's no telling who could join the show. Luckily, there are a few leading candidates for future Legends.This Page: Constantine and The Ray

Constantine

John Constantine holding out his arms.

One of the most obvious characters on the list of Firestorm replacements is John Constantine. After NBC's Constantine was cancelled, it seemed for a moment as if the CW could pick it up. Instead, the character simply made an appearance on Arrow, where he helped Sara get back on track after her dip in the Lazarus Pit.

Along with the original show landing on CW Seed, Constantine is now considered part of the Arrowverse. Thanks to that, there will soon be a Constantine animated series with Matt Ryan returning to voice the character. All of that would be reason enough for him to join the Legends, but his cameo at the end of the midseason finale sets things up even better.

The midseason premiere of Legends of Tomorrow will see Constantine joining forces with the team, and it's not hard to imagine the arrangement becoming permanent. Constantine's personality would fit nicely with the group and he'd be a fitting powerhouse to replace Firestorm. And with the Darhks, Mallus, and Kuasa all steeped in the supernatural, having a sorcerer aboard the Waverider makes sense.

The Ray

The Ray looking intently in Crisis on Earth-X

Before word broke that an established Arrowverse hero would replace Firestorm, the loss of Jax seemed inevitable with Stein leaving. Crisis on Earth-X, meanwhile, seemed to provide the perfect addition to the Legends when Citizen Cold decided to stick around. It appears, however, that Leo Snart will be one of two new additions to Legends of Tomorrow when it returns. We know Wentworth Miller will soon leave the Arrowverse, so we can't expect him to stay onboard for too long, but perhaps he'll swap places with his partner.

While Freedom Fighters: The Ray just dropped, Russel Tovey made his live-action debut as The Ray during the crossover. Like Vixen before him, the opening is now there for him to return to the Arrowverse outside of animation. Granted, Mari has been back, but The Ray would be a nice analogue for Firestorm and a nice match for his powers. The Ray would provide a good way to leave the door open for Snart to return if Miller ever decides he's made a huge mistake.

Nyssa al Ghul Arrow

Nyssa al Ghul

As the opening of Legends of Tomorrow continues to hammer home, the characters of the show aren't heroes. Snart and Rory are both criminals and Sara's an assassin. As such, it makes sense that the net for a Firestorm replacement for Firestorm would be cast beyond simple do-gooders.

Since the early days of Arrow, Nyssa al Ghul has been a recurring presence on the show. She taught Sara everything she knows, and also served as her one great love. While Alex Danvers boarding the Waverider would make for a great pairing with White Canary, she's too intrinsically tied with Supergirl to ever leave. Sara's tryst with Alex, however, did reveal something else: she's still holding a candle for someone.

Related: Legends of Tomorrow: Is Captain Cold Sticking Around?

Caity Lotz has said she wants Sara to have a real relationship soon. While some believe this could be Agent Sharpe, the return of Nyssa to Sara's life would have much more emotional and narrative significance. And adding an archer to the group would be a nice way to tie Legends of Tomorrow back to the show that began the Arrowverse.

Justice Society of America

Legends of Tomorrow - The Justice Society of America

If Legends of Tomorrow is looking for a familiar, established character, Vixen's former teammates seem like a good place to start. Last season made a big deal about introducing the Justice Society of America before mostly relegating them to a few minor appearances. Vixen joined the team, but a number of other members died or never got a proper spotlight. Any one of those heroes could come aboard the ship, tying Vixen back to her past and opening the door for more fish-out-water humor.

Stargirl in particular would be a nice addition given the many powers she possesses due to her staff. With it, she could help fill the power vacuum left by Firestorm. Similarly, Doctor Mid-Nite's tech and somber personality would add a nice flavor to the show, while Obsidian could return thanks to the ever faithful time-travel. The arrival of the latter hero would also set up an appearance by his father, original Green Lantern Alan Scott. Pulling the JSA back into the Arrowverse would be a great way to expand the scope of the world, and any one of the more strident heroes would make a nice addition to the time-traveling gang of misfits.

Kid Flash

The Flash Season 3 Midseason Premiere Kid Flash Wally West

Earlier this season, we made the case why Kid Flash should join Legends of Tomorrow. All these weeks later, and it now seems the smartest bet. While we won't retread what's already been said, it's worth repeating how perfect a speedster would be on the team. He would easily help balance the scales after Firestorm's departure and Wally's engineering background would fill the gap left by Jax”after all, who else knows how to fix the Waverider?

The time since we made our original case has seen Wally be virtually absent from The Flash. He's sat out multiple episodes, seeming to set up his arrival on Legends of Tomorrow only for nothing to happen. He did gloriously return for the crossover, demonstrating his unique fighting skills and distinguishing himself from Barry. But he was quickly sidelined when he was asked to protect Iris and Joe and he never returned. The midseason finale of The Flash reduced him to a name-drop, so him showing up on Legends of Tomorrow seems to be the only way for the hero to get any screen time.

From his personality to his skills to his powers, Wally would be just about the perfect fit on the Waverider and a fitting replacement for Firestorm. And with Mallus' forces gaining momentum, a speedster could be the perfect weapon in the Legend's war against evil. From the more obvious options we've named to a dark horse candidate, the Arrowverse has no shortage of heroes and heroically-adjacent characters that could replace Firestorm. And with only two months until the return of Legends of Tomorrow, expect word of the newest addition to the team to arrive before long.

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