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.
Given 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
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.
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.