Fans called it The Snap. The surviving inhabitants of the Marvel Cinematic Universe have a harsher name for it: The Decimation. Thanos won at the end of Avengers: Infinity War, wiping out half of the world's population in the name of "balance." The Mad Titan's victory won't be permanent. It can't be, given Spider-Man: Far From Home and Black Panther 2 are already on deck for Phase 4 and it's incredibly unlikely Disney would release two films about piles of ashes. Getting to the point of defeating Thanos and undoing his horrible triumph, however, is sure to be an incredible struggle. Therein lies the suspense for Avengers: Endgame, hitting theaters in April 26, 2019.
Defeating Thanos, in all likelihood, is not a task that could possibly be accomplished by one hero alone. Teamwork is the main theme of the Avengers films, so of course the fight will be a team effort. That said, it would appear that certain characters are more likely to be and/or capable of contributing to that victory in bigger ways than others. This list goes through 20 characters (19 survivors of The Decimation plus the one hero who is the most likely to recover from it first) in order from the lowest to the highest likelihood that they'll directly take down Thanos in Avengers: Endgame. As this is all speculation, don't take any of the theories in this article for confirmed spoilers, but do be warned that the number one entry does contain spoilers to the 27-year-old The Infinity Gauntlet comics storyline in its reasoning.
20 HOWARD THE DUCK
Someday Howard the Duck may rise above a series of glorified cameos. It's so established that Marvel Studios can turn anything into a hit that it shouldn't a stretch to see them fully redeeming a character known best in the mainstream for a lackluster George Lucas bomb in the '80s. That day, alas, is probably not April 26.
The Russo brothers have confirmed that Howard the Duck is one of the survivors of The Decimation, so technically he could show up and help save the day. A cameo seems possible. Him actually being useful seems a bit less likely, but can't a duck dream of something greater?
19 RED SKULL
OK, for this one, you have to ignore the "hero" part of this article's title. Red Skull is a bad guy and it would not be a good look for Marvel to try to redeem the former head of H.Y.D.R.A. He doesn't have to be redeemed, though, for him to potentially be useful in defeating an even greater evil.
Since Red Skull became the keeper of the Soul Stone, he might possibly be positioned to take the Soul Stone back from Thanos. Perhaps on some technicality Thanos' sacrifice ends up being deemed unworthy, or perhaps Thanos himself tries to cheat and undo said sacrifice?
18 CASSIE LANG
Ant-Man and the Wasp foreshadowed Cassie Lang's future as a superhero so heavily it was almost a surprise she didn't get into the action in the third act. Marvel could be saving that for the third Ant-Man movie, but credible rumors suggest that Cassie Lang's daughter could be playing a bigger role in Avengers: Endgame.
Emma Fuhrmann is cast to play an older version in Avengers: Endgame. She'll almost certainly be included as part of some sort of time travel story line. It's possible that as one of her superhero personas, Stature or Stinger, she could join in the fight against Thanos, though likely not in a major role.
17 NAKIA
One of the few new details revealed in the Avengers: Endgame trailer is that Shuri is "missing." She could be secretly alive, as Angela Bassett has claimed, but it seems all too probable she's been Decimated. If Black Panther's little sister is out of commission, however, might his ex-lover Nakia be around?
Nakia was one of the most notable no-shows in Infinity War. Supposedly she was on a secret mission during the time of Infinity War, and it's likely we'll learn more about that in Endgame. Maybe she didn't survive, but perhaps she's gathered some important intelligence. She could even serve as Black Panther in T'Challa and Shuri's absence.
16 WAR MACHINE
Of the main Avengers team, War Machine seems among the most likely to bite the dust. Frankly, it's kind of surprising he's still alive, and in good enough health for superhero work at that. His brutal injuries in Civil War sure seemed like they could have had significantly worse results.
As one of the few survivors of the Decimation, he'll certainly get at least some sort of cool heroic moment before he goes, maybe one which is vital to defeating Thanos. Still, with the character not particularly beloved and Don Cheadle the oldest of the main hero actors, it's doubtful he sticks around in the MCU much longer.
15 VALKYRIE
The Asgardians have had the worst time lately. They've lost their home planet, and their population was decimated even before The Decimation. Joe Russo has confirmed that Valkyrie was among those who escaped before Thanos' slaughter, and Tessa Thompson has been on set for Endgame.
Valkyrie is certainly a fighter the Avengers would want on their team. The big question is where she's at psychologically. She was just starting to get out of a funk of defeat in Thor: Ragnarok. Will losing so many people once again send her into despair, or will it make her more driven for revenge?
14 THE ORIGINAL GUARDIANS
Even if the actual Guardians of the Galaxy Vol. 3 doesn't happen for a long time, Marvel is unlikely to abandon all of the credits teases from Vol. 2. The main Guardians team is gone except for Rocket and Nebula, but it's possible that the original Guardians team, whose reunion was one of Vol. 2's many credits scenes, could be in action.
Tony Stark's going to need all the help he can get drifting through space. While Captain Marvel might be the obvious choice to rescue him, don't count out Stakar Ogord and company saving the day and becoming powerful allies to the Avengers throughout the galaxy.
13 BLACK WIDOW
Unlike some other Avengers, Black Widow having an upcoming solo movie is not a promise that she will survive Endgame. The Black Widow movie is a prequel set in 2005. Either it's set in the past because nobody's willing to make a female superhero movie set in the present, or there's an actual plot justification in that Black Widow won't be alive in the near future.
Of course, given what a major recurring presence Black Widow has been throughout the MCU, it's almost certain that she'll get a powerful send-off. One fan theory suggests her relationship with Banner will get some narrative pay-off, with her being instrumental in helping Banner regain his ability to Hulk out.
12 ROCKET
Rocket's arc throughout the MCU has been evolving from a scoundrel to a true hero, casting off the self-loathing that was holding him back. If he has reason to hope that he can save his Guardians family from nonexistence, perhaps with a little encouragement from his new friend Thor, then Endgame is the perfect opportunity for him to demonstrate his heroism.
Rocket's small stature gives him a distinct disadvantage in battle compared to the other heroes, but it's also a trait that can come in handy in cases. His ability to hatch elaborate schemes could also come in handy. If he doesn't make it out alive, at least he'll have done enough to earn a funeral like Yondu's.
11 RONIN
One of the Russo brothers' big responsibilities with Endgame is to make Clint Barton necessary to defeating Thanos. Age of Ultron might have developed him into an interesting character, but he's still been the odd one out among the Avengers given his lack of powers.
Given his complete absence from Infinity War, the pressure is on for Barton's big return (and possible swan song?) to impress. Traumatized by the loss of his family, he's escaped house imprisonment and abandoned his Hawkeye persona in favor of the new identity of Ronin. It remains to be seen how he'll fight Thanos, but he'll certainly be motivated.
10 ANT-MAN
Up to this point, Ant-Man's main purpose in the MCU has been comic relief. Even in the Endgame trailer, his appearance at the end is the only moment of levity amidst the deathly serious tone of the rest of the teaser. Still, the fact he does appear, that he somehow escaped the Quantum Realm without the help of the Decimated Pym-Van Dyne family is something of undoubted significance.
Perhaps accessing the Quantum Realm ends up instrumental in the time travel-based plot to recover the Infinity Stones and defeat Thanos. The location of that leaked concept art is uncertain, but it might possibly take place in the Quantum Realm itself, which would mean Ant-Man will shrink the rest of the Avengers down there.
9 SKRULLS
One rumor claimed that Avengers: Endgame's plot involved the surviving Avengers teaming up with "an unlikely ally." This rumor got the title of the movie wrong, but considering finalized titles are often last-minute decisions in Hollywood, there's a chance it might be legit. Perhaps Captain Marvel, whom they'll be meeting for the first time, might be considered "unlikely"... but what if it's her enemy, the Skrulls?
If any Decimated heroes were actually Skrulls, that would mean the Skrulls unintentionally helped some additional heroes survive. Although the chaos of The Decimation offers an opening for the Skrulls to conquer Earth, remember, The Decimation affected all lifeforms, and it's possible even enemy species could form truces to fight a mutual threat.
8 DOCTOR STRANGE
Of those heroes lost in The Decimation, odds are highest on Doctor Strange being able to figure a way back. "We're in the endgame now" was his line in Infinity War, and he could very well be the mastermind behind the path to victory in Endgame. The Russos have confirmed on their commentary track that Strange knew exactly what he was doing with all of his decisions in Infinity War.
If the Decimated heroes are in fact sent to the soul world or some other dimension, Strange knows his way around dimensions. If time travel is the solution to defeating Thanos, he has experience with that as well. Whether he defeats Thanos or merely leads others to victory, he'll be vital to saving the day.
7 PEPPER POTTS
The Endgame teaser opens with Tony Stark recording a message for Pepper Potts. Not only does it seem almost certain she'll end up seeing that message, but it's incredibly likely she ends up saving him at some point. She's already done so in Iron Man 3. If their romance is back to the forefront again in Endgame, Pepper has plenty of opportunity to be a hero.
It's already confirmed that Gwyneth Paltrow has filmed some motion capture scenes for Endgame. What else could those be for except Pepper wearing an Iron Man suit, likely in some important heroic moment? This could be the official screen debut of her superhero persona Rescue.
6 IRON MAN
In the Endgame teaser, Tony Stark is prepared for the end. Of course he's going to find some form of rescue from being stranded in space, but it's still likely the end will come for him at some point during Endgame. If the MCU's first big screen superhero is going to go out, though, it's sure to be with a bang.
Concept art shows Stark will get suited up in some Iron Man armor again in the movie. Even without his regular tech, though, his inventive genius is sure to be useful in defeating Thanos. One popular theory is that he'll build his own copy of the Infinity Gauntlet, wieldable by the Hulk to steal the Infinity Stones.
5 THOR
It's become increasingly clear over the years that Thor is one of the coolest heroes in the MCU. He's proven himself able to keep going even in the face of unimaginable losses, and with his new hammer Stormbreaker, he got far closer than anyone else to actually defeating Thanos.
If Thor gets a rematch with Thanos, does he go for the head and win? There's certainly a chance. If the goal is to end Thanos, Thor might deserve an even higher ranking. For certain reasons (to be elaborate in the number one entry), there might be reason to try to capture Thanos alive, for which other heroes might be slightly better equipped.
4 HULK
Hulk smash good. In first Avengers, Hulk smash Loki. Age of Ultron, Hulk smash too much and leave planet in shame. Thor: Ragnarok, some great smashing. Infinity War, though, Thanos smash Hulk! Then no Hulk for rest of movie, only puny Banner!
Endgame, Hulk will smash! Rumors say Professor Hulk will smash, in which case the Hulk will be smashing with much more sophisticated grammar than previous forms of the beast. Even if Thanos can beat Hulk in sheer strength, if Hulk has Banner's strategic intelligence and is wielding the rumored Stark Gauntlet, Thanos could very well get the Loki treatment.
3 CAPTAIN AMERICA
We already know Chris Evans is leaving the MCU following Endgame. This means either Captain America sacrifices his life while saving the world, or he somehow survives and enjoys a well-earned retirement. Either would be an amazing send-off to the most purely heroic of Marvel's superheroes.
Cap's screentime in Infinity War was fairly limited, but it was defined by persistence. Even when completely outmatched by a Gauntlet-wielding Thanos, he keep fighting until he couldn't stay standing. His leadership will be essential in rallying the team of surviving heroes. If Thanos is somehow weakened, Cap's persistence might just pay off in a rematch.
2 CAPTAIN MARVEL
In the face of his own demise, Nick Fury's final act was to call upon Captain Marvel from the reaches of deep space. While she is not featured in the Endgame teaser, she'll undoubtedly be an essential part of Thanos' defeat. She's a connection between the Earth-bound and the intergalactic heroes. According the filmmakers, she's more powerful than hero seen before in the MCU.
If she's so powerful, why is she only at number two on this list? Well, power is all well and good, but power rankings and plot developments aren't the same thing. While Captain Marvel's power guarantees her usefulness in defeating Thanos, in terms of narrative interest, there's one character who has more compelling reason to defeat him...
1 NEBULA
The answer to who defeats Thanos might already be staring everyone in the face. Infinity War wasn't a strict adaptation of The Infinity Gauntlet, but if Endgame sticks remotely close to the classic comics storyline, the greatest threat to Thanos is his daughter Nebula. Nebula knows Thanos better than anyone else, and can exploit her father's weaknesses.
Of course, her stealing the Gauntlet from her dad won't necessarily make the universe any safer. In the comics, after she takes on all that power, several Avengers have to team up with Thanos to stop her. Maybe the better question isn't "which hero is most likely to defeat Thanos," but "which hero is most likely to defeat Nebula?"