With the Arrowverse's next crossover shaping up to be the biggest threat the heroes of The CW's multiverse have ever faced, it seems inevitable that not everyone will make it through this one. Last year's "Elseworlds" crossover event nearly ended with the deaths of both Supergirl and The Flash. Before that 2017's "Crisis on Earth-X" resulted in the death of Legends of Tomorrow character Martin Stein. In fact, we already have confirmation that at least one major hero likely won't be returning home at the conclusion of next year's epic crossover event. The question is, who might not make it this time? While there are tons of heroes across the Arrowverse, here are the ten heroes fans should be worried about.
10 Kid Flash
Wally recently left The Flash to pursue his own interests away from the influence of others. Still, Wally remains a hero who is always willing to help someone in need. When a threat to the multiverse comes, it would be rather surprising if Wally didn't run to meet it. The Flash's creative team has struggled to give Wally a sense of identity and he often feels relegated to the sidelines so that Barry can save the day. Killing Wally would have an impact on fans of the character while removing the need for the writers to constantly attempt to explain the character's absence. It would also give the character one final chance to make an impact as a hero.
9 The Flash (Earth-3)
While there is no confirmation at the moment as to who might be involved in the crossover, it seems obvious that the heroes of Earth-1 will seek aid from allies around the multiverse. Last fans heard of Jay Garrick, he had been training a replacement to protect his Earth. Despite his willingness to retire, we'd bet Jay would be more than willing to step up to the plate when the entire multiverse is threatened. Killing Jay would allow the writers to give fans a death with little lasting impact on the status quo of any of the major series, but that would still be a shot to the heart for many fans. Given John Wesley Shipp's willingness to return to the show, it seems likely that he'll appear.
In last year's "Elseworlds" event, Kara didn't hesitate to put her life on the line to save the planet. With an even greater threat looming, you can bet that she'll be ready to do it again. Despite being one of the multiverse's most powerful heroes, Kara is not invincible. While Supergirl has already been renewed for another season, an episode count has yet to be released, meaning that Supergirl could receive a smaller run if Kara's death is on the horizon. It's worth noting that Supergirl was among the casualties in the "Crisis on Infinite Earths" comic event, so a precedent for her death exists. As one of the most charming and fun characters in the Arrowverse, her death would definitely be felt.
7 Mr. Terrific
Over the course of his history on Arrow, Curtis has made huge developments as a character. So huge in fact, that we're not entirely sure where else he can go next. He has sacrificed his relationship with his husband for the good of Star City and continues to be driven by a sense of duty to those around him. Unlike many of the cast of Arrow, Curtis has yet to appear in the "flash-forward" episodes this season. While other characters like Oliver and Diggle are also absent from those sequences, it's notable that they seem to focus heavily on newer additions to Team Arrow yet exclude Curtis. This could be an indication that Curtis doesn't make it to the future. Given the rather inflated cast Arrow has at the moment, it wouldn't be too surprising to see Curtis become an unfortunate casualty of the Anti-Monitor to drive home the threat he poses.
6 Elongated Man
Over the course of his time on The Flash, Ralph has grown into a capable hero. The thing is, he is a perfectly fine hero among several other better heroes. While season 4 was heavily focused around Ralph's transition from a washed-up private investigator to the hero and his importance to The Thinker's plans, he doesn't really have much of a purpose anymore. The Flash already has a pretty crowded main cast and if the team at CW is looking to trim it down a bit, Ralph is the obvious choice. Given the threat coming to the multiverse and Ralph's willingness to do anything to protect his new friends, we wouldn't be surprised if the Elongated Man's time in Central City is coming to a close.
5 Martian Manhunter
J'onn has had quite an interesting journey on Supergirl and has quickly become one of the show's most beloved characters. One of his defining characteristics is his willingness to protect people, especially those he cares about. While he is currently abstaining from violence, he would probably make an exception for a threat like the Anti-Monitor. In such a threat, J'onn wouldn't hesitate to lay down his life to protect the innocent and it will almost certainly come to that. He has served as a mentor and friend to many of the characters on Supergirl, so his death would certainly prove to be a powerful motivator to stop the Anti-Monitor.
Diggle has long been a mainstay of Arrow, but that could be coming to an end. If the creative team wants to make an impact without killing off a headlining character, Diggle would be the perfect candidate. One of the Arrowverse's oldest characters and a close ally to several major heroes, Diggle's death would deal a huge blow. Besides causing a huge impact, his death could also be a form of paving the way for another major character's introduction. In "Elseworlds," Earth-90's Barry Allen recognized Diggle and remarked that he, "wasn't wearing his ring." This was obviously a nod to some fans questioning if Diggle could become Green Lantern. While Hal Jordan is probably the most famous Green Lantern, another by the name of John Stewart exists in DC Comics canon. Fans have pointed out that Diggle somewhat resembles Stewart, and both share the same first name. It's possible that the reference in last year's event could serve as foreshadowing for the future. If that's the case, the CW may use Diggle's death to introduce an alternate version of the character as a Green Lantern.
3 The Flash
Barry Allen's entire life has been leading to this moment. From the earliest episodes of The Flash, fans have been aware that Barry is destined to disappear in a crisis, never to return. As "Crisis on Infinite Earths" fast approaches, it seems that Barry Allen may finally have to face his destiny. Despite numerous changes to the foreboding news piece that acts as a prophecy for Barry's future, one thing has remained consistent. He will disappear. That fact has never changed. While the intervention of his daughter, Nora, in his past has caused changes to the timeline, the article's headline remains unchanged and with numerous speedsters available in the Arrowverse to take up his mantle, Barry Allen's time may be coming to an end.
At the conclusion of "Elseworlds," Oliver made a deal with the Monitor to save Barry and Kara. As the Monitor is obsessed with balance, you can bet he's going to collect. While the terms of the deal are left unknown, it seems obvious that it would include a major sacrifice to be made. As Arrow continues to take strides in bold new directions, it doesn't seem out of the question that an Arrow without Oliver Queen could be in the cards. The show has built a strong supporting cast who are more than capable of carrying the show on their own. Given that thus far Oliver has been absent from the "flash-forward" segments of the show, it certainly seems that he may well not be returning home from this particular adventure.
While not a regular cast member of any of the CW's shows, Superman certainly fits the bill as a major superhero. The Man of Steel is one of the most powerful heroes in the multiverse, but he's also one of the most likely to lay his life down for the sake of others. Though he is currently sidelined as he awaits the arrival of his first child with Lois Lane, fans can expect his return for "Crisis on Infinite Earths" given his integral role in "Elseworlds." Using Superman as their sacrificial lamb would solve a lot of issues for the writing team and enable them to have a tragic moment that resonates with fans without killing off a headlining hero. Notably, an alternate version of Superman sacrifices himself in the comic event, so using Earth-38's Clark Kent would be a great nod to the source material.