Who should beat Thanos in the upcoming Marvel film Avengers 4: Endgame?

Thor

Thor got really close at defeating Thanos at the end of Avengers 3: Infinity War and while his partial responsibility in Odin's death contributed to the Mad Titan's victory, as Odin was too powerful for Thanos to defeat while collecting the Infinity Stones, Thor could just get accustomed to using Stormbreaker, his new hammer that is much more powerful than the previous one that Hela owned before Thor and destroyed in Thor 3: Ragnarok, and then his expertise in using Stormbreaker alongside the fact that the Infinity Gauntlet of Thanos was constructed from the same person, Peter Dinklage, while Thanos will not know to use it well after his infamous snap, could be enough for Thor to beat Thanos by himself.

Iron Man

Iron Man is credited as the one who gave birth to the Marvel Cinematic Universe as well as the Avengers, the legendary team where it was he who invited Hulk, Thor and Captain America to become Earth's mightiest heroes. He is also rumoured to be expecting Pepper's child so he is more motivated than his allies in defeating Thanos, especially Thor who has fallen into despair after losing his father Odin and Loki not a long time after the death of his mother and his separation with Jane Foster or Hulk who might be afraid that getting angry enough to beat Thanos may probably make him much more dangerous than the Mad Titan. Doctor Strange who could see the only future where Thanos was defeated also left his outspoken rivalry with Iron Man aside and volunteered to sacrifice his life as well as half the universe's population so that Iron Man may live to fight another day, so he must have some contribution in the downfall of Thanos, but what if he is not only the guy who helps beat him but the one who does it single-handedly too? He has created dozens of specialized armored suits including a Hulkbuster that impressed Banner, so why not create a Thanosbuster with the aid of his friends and go find Thanos and put him down for good?

Hulk

Bruce Banner was very reluctant about transforming into the Hulk but due to villains becoming bigger and bigger, not only in numbers but also in power, he understood that the Hulk was the last thing that his friends should worry about, so he became less reserved and insecure in being the Hulk, the strongest Avenger. Therefore, alongside the fact that Hulk wants to prove that he is the strongest one there is, with the only way to do being smashing all supervillains there are, Banner almost got in terms with his Hulk, but unfortunately, at the beginning of Avengers 3, Hulk experienced his first defeat at the hands of Thanos, and was hesitant in re-emerging, even after Banner was begging him to do so. But his defeat could only be a result of not being angry enough, as he was inside a ship with his Asgardian friends that he was not fighting against in order to become more powerful until Thanos arrived and slaughtered almost all of them. Even in the previous avengers films Hulk got strong enough to smash the bad guys after a confrontation with an ally, the first being with Thor upon the SHIELD helicarrier, the second being with Iron Man's Hulkbuster armor. So if his friends take him on a war-torn planet, he will become the notorious World Breaker, and draw the attention of Thanos whose arrogance due to both his satisfaction over his personal success and his previous easy victory over Hulk that could lure him into underestimating him could be the only thing needed for putting an end to Thanos and his reign of terror. His divided personality could also prevent him for abusing the Infinity Gauntlet's power after retrieving it from a defeated Thanos, so Doctor Strange might in fact lead to this scenario not because it was the only one where Thanos was defeated, but even if there were many ways for Iron Man or Thor to beat him, Doctor Strange realized that it would not be a victory, because the vast potential of the Infinity Stones could corrupt the noble but vulnerable personalities of the other heroes and tempt them to abuse them just like Thanos, while Hulk who did not participate in the Civil War could be the right guy to beat Thanos, because the only thing he would care about is erasing the timeline where he had his embarassing defeat from Thanos, thus saving the lives of all dead heroes, including Doctor Strange himself, while he could destroy the Infinity Stones merely as a result of his desire to not allow anyone be stronger than him.

Hela

What happened to Hela at the end of Thor 3 is a complete mystery but it has been speculated that she might still be alive. Hela is also known to be very powerful so her absence may be the only reason that Thanos was victorious, which is indicated by the fact that he attacked immediately after Hela was caught in a battle against Surtur that Thor provoked while ignoring the threat of Thanos, who by that time started collecting the Infinity Stones and soon after had a complete gauntlet in his grasp. Thanos was the main villain for years but did not dare confront his enemies so directly, putting pawns such as Loki or Nebula do his bidding instead, but because of Hela's imprisonment, it was Odin that Thanos probably feared, not Hela, but even after Loki managed to fake his death at the end of Thor 2: The Dark World and dethroned his father, Thanos was still hiding. So after Hela is finished fighting with Surtur, she could very well take on Thanos, who has never before faced anyone as powerful as Hela, so losing such fight is a real possibility, with Hela doing to the Infinity Gauntlet the exact same thing she did to Thor's hammer, as she is very confident in her own powers and discarded a duplicate of the Infinity Gauntlet as useless while in Asgard.

Dormammu

Dormammu is undeniably one of the most powerful beings in the Marvel Universe so it would be no weird thing if he actually is the one to beat Thanos even with the Infinity Gauntlet, so what if Doctor Strange sacrificed his life as well as the Time Stone because it was the only thing keeping Dormammu in check, but the destructive potential of the Infinity Stones made his return a neccessity to end a threat even greater than he? Thanos could probably be unable to use the Infinity Stones due to Dormammu's extradimensional nature so his victory could be inevitable to prevent anyone from using their limitless potential. The return of Dormammu could also convince Doctor Strange's order of sorcerers to grant him more power after losing the invaluable Time Stone that had a sacred value in his order, given his success at beating him before.

Galactus

The conclusion of the storyline involving Thanos is the end of an era, an era that could be the very same era since the very start of the franchise, so many questions have been raised. What happens after? Who is going to be the villain? What new challenges will the heroes have to face? Who could be more powerful than all these villains who have layed destuction in their path in all the previous entries in the Marvel Cinematic Universe? Will new heroes be introducted? The answer to all of the above could be Galactus, a nigh-omnipotent entity who is the last survivor of the previous universe and wants to survive until the end of ours at any cost, so even if he does not have evil motivations, his unmatched power and his need to sustain it led him into destroying entire planets in order to satisfy his eternal hunger, making him one of the greatest enemies of the Fantastic Four, a team that could be introduced soon now that 20th Century Fox that had property rights on them is being bought by Disney that produced the mainstream Marvel films. Also the death of half of the universe's population restricted the universe's resources for him even if it was meant to prevent them from being depleted by mortals. And due to the fact that he is not primarily evil, he also has a herald that chooses the worlds to consume for him, so he actually cares about not killing those who should live, so if he does not agree with the judgment of Thanos about who should live and who should not, he could very well hold a deep grudge for Thanos and come after him to end his reign of terror, but also destroy Earth, because he probably puts the blame in our world for not defeating Thanos and allowing him to become a threat to the universe, so for Galactus, the salvation of the universe might not be determined on whether Earth lives or not, so in his perspective, humans are the bad guys and he is the good guy.

Silver Surfer

Silver Surfer was a herald of Galactus and a regular ally of Earth's superheroes while being much more powerful than them, so Earth's failure to defeat him might urge him to arrive on our planet and aid the Avengers in defeating him. But unlike Galactus, his former herald is much more concerned in the affairs of mortals such as humans and by the time he defeats Thanos, he will already be a friend of many people from Earth and learn enough things about humanity to grow fond of it and therefore he will not desire its destuction. So this could be the reason he relinquishes his duties as the herald of Galactus and becomes one of the strongest protectors of Earth. If Surfer could not understand humanity as well as every other civilization he encounters much better than Galactus, why would the latter choose the former to be his herald?

Magneto

According to Wolverine actor Hugh Jackman as well as millions of fans, X-Men are bitterly missed and overlooking them is not the right thing, so with Quicksilver and Scarlet Witch being the only ones from the X-Men storylines to be introduced into the Marvel Cinematic Universe as well as the children of Magneto, a prominent villain of not only the X-Men but the rest of the heroes as well and has recently decided in the comics as well as film to radically change direction and become more heroic, redeeming himself from many of his past atrocities as an enemy of his fellow mutants, could be the first main character from the X-Men saga to arrive into the mainstream Marvel film continuity. And the only reason he has been a bad guy despite his capacity and desire to do good is because of his fear that mutants need protection and the only way to ensure that is by turning against the rest of the human race. So considering the long absence of the X-Men in the films while they have saved the world as many times as the Avengers in the comics, it is almost a certainty that if they are to be introduced some time in the future, they did not exist during the events of the previous films. Therefore, Magneto's arrival that could be the only way to defeat Thanos, will probably not establish him as a hero as great if not greater than the Avengers, but a threat alongside the mutants he represents, thus laying the foundations of the constant theme of mutants being persecuted and feared that has been featured in most X-Men storylines.

Captain Marvel

The recently introduced heroine is said to be the most powerful of her Avengers teammates so considering the upcoming film where she is revealed to have existed many years before most of the other superheroes, defeating Thanos might be the right way to earn her rightful place as the greatest of Earth's protectors. A lot has transpired since the events of the Captain Marvel film so Thanos could be the only reason she would return to Earth after improving her powers and skill in using them all those years she has been with the Kree, the race who provided her with all the amazing powers she possesses while knowing many things about the nature of the Infinity Stones, proven by the fact that Ronan the Accuser, the main villain of the first Guardians of the Galaxy film, is a prominent member of their race and owned the Power Stone, the first Infinity Stone to be collected by Thanos. So the defeat of the Mad Titan at the hands of Captain Marvel could probably not make her seem too powerful, as it will be a result of her understanding of the cosmic energy of the Infinity Gauntlet as well as Thanos himself and not overall power.

Grandmaster

Jeff Goldblum's character who first appeared in Thor 3 is known to be extremely powerful and the only reason that he has not caused unimaginable destruction across the universe is because he is not interested in conquering or ruling the universe, as he considers himself to be much above it, but instead loves playing with mortal slaves that he keeps captive in his Contest of Champions, a domain that seems very similar to the Battleworld from the comics. But since Battleworld was not the realm of the Grandmaster, who is blue-skinned in the comics, but instead is a creation of the Beyonder, who surprisingly has a striking physical resemblance with Jeff Goldblum, sharing his trademark curly dark hair, there could be an amalgamation of the two characters that are each considered in their own right as top ranking entities in lists of the most powerful beings ever to exist, so the Grandmaster/Beyonder could temporarily abandon his prankster behaviour with the heroic deed of being the one who beats Thanos, only for enslaving many of superheroes immediately after, as the only problem he probably has with Thanos is killing half of the universe's population, possibly including some that he wanted to take with him and include them in his games that he always loves to play.

Mephisto

The enemy of Ghost Rider, who has actually been introduced in Agents of SHIELD, the TV series that is adjunct to the movies, is Marvel's own version of Satan, who is obviously more evil than Thanos and rules his own dimension where the souls of the dead are kept for all eternity, so now that in a mere moment Thanos has, probably inadvertedly, provided him with an uncountable number of souls that died from his snap, he is quite likely stronger than ever before, so considering the fact that he always had vast power rivaling Thanos, it could be no surprise that if in the movies he exists as a replacement of Death, who in the comics was another ruler of a different realm of the dead that Thanos wanted to serve in order to earn her favor by killing half of the universe's population not for preserving its resources but for satisfying her instead, Mephisto could easily destroy Thanos in the upcoming Avengers 4 film.

Namor

While for all those years that the Marvel Cinematic Universe is running there has been no competition and record after record has been broken, now that a huge storyline has reached its conclusion, the continued success of Marvel is not guaranteed in the future, so with Aquaman being a huge box office success that revived a longly dormant DC Universe that is a huge competitor of Marvel, it is highly likely that there should be many changes in order to keep up with the emerging DC film series, so one of them would be to bring their own version of Atlantis. Namor is one of the few Marvel characters who has not been stolen from DC but Aquaman, who is the king of Atlantis just like him, is the DC counterpart of the first ever Marvel superhero and pretty much a copy of him. So with many fans holding a grudge on Marvel for its huge dependency on characters copied from DC (Hulk copied from Solomon Grundy, Thanos copied from Darkseid, Magneto copied from Doctor Polaris, Doctor Strange copied from Doctor Fate, Vision copied from Red Tornado, Ultron copied from Brainiac, Quicksilver copied from Flash and Hawkeye copied from Green Arrow) a way for Marvel to redeem itself from that and prepare for a huge cinematic rivalry with DC would be to give Namor a major push. One of the most notable differences between Namor and Aquaman is that Namor does not have a trident of Poseidon just like Aquaman or any weapon like other heroes, such as Thor who has a hammer, Wonder Woman who has a lasso and Captain America who has a shield. So what if he actually had some powerful magic weapon but used it to defeat Thanos and then lost it, thus developing a mistrust of surface dwellers for forcing him to sacrifice that sacred artifact of his kingdom because it was the only way to save the universe from absolute destruction, even if he is a half-human Atlantean hybrid just like Aquaman?

Red Skull

Red Skull is the main villain of Captain America and has tormented the iconic hero in the present day as much as during World War 2, so his apparent death in the first Captain America movie should not last for long, but it did until he was shown in a short scene in Avengers 3 where he forced Thanos to kill Gamora despite quite surprisingly the fact that Thanos felt genuine love for her in order to be granted Soul Stone from Red Skull, so considering the fact that Red Skull would never help anyone without serving his own schemes, what if giving Thanos the Soul Stone was actually part of his plan to take over the world, but for doing that he should ensure that the Avengers would not be there to stop him, which he did by helping Thanos become a major threat, while keeping an ace up his sleeve considering the fact that he was teleported out of Earth by the Tesseract, which is fact was another one of the Infinity Stones, specifically the Space Stone that Loki used in his staff, so with all those decades of his exile from Earth, it would be no surprise that just like he became one of the most dominant people on Earth who almost conquered the entire planet, he could spend an even longer time than on Earth to learn many things about the universe, thus knowing a way to defeat Thanos so that he finishes what the Mad Titan started but instead keeping for himself whatever Thanos had conquered along the way.

Loki

Loki is speculated to have faked his death yet another time, so considering the fact that he used to be an ally of Thanos in the first Avengers film, he might have stayed in hiding only because he waited for Thanos to take the Infinity Stones and then arrive out of nowhere to claim them for himself, thus manipulating him in the same way that he has constantly brought suffering to Thor. Considering that Malekith, the villain of Thor 2, threatened to destroy the universe just like Thanos by using one of the Infinity Stones, specifically the Reality Stone, and Loki aided Thor, surprisingly on Thor's own request, to defeat Malekith before finding an opportunity to strip Odin of his throne in Asgard, the exact same thing could happen with Thanos. Loki has been a huge box office draw from the very beginning, and considering the fact that we at the end of an era with the next one possibly not belonging to Marvel but to DC instead, it would probably be suicidal to waste one of the most iconic villains, and an exception to the constant trend of villains dying a short time after their debut and not returning to life, unlike the comics.

Mandarin

Mandarin is the greatest villain of Iron Man, arguably the main character of the Marvel film series, who was replaced in the third Iron Man movie by an imposter, portrayed by Ben Kingsley, who was actually a puppet of Advanced Idea Mechanics (AIM). This caused a huge outrage among fans and even if the movie was more successful than its two predecessors and Aldritch Killian, the leader of AIM, was considered a great villain, the reluctance of Marvel to introduce Mandarin could be the reason there have been two Captain America, two Thor, two Ant-Man and two Avengers movies without another Iron Man film despite the former two preceding all the others apart from the Incredible Hulk and the fact that Iron Man was more popular and his solo film series grossed more at the box office, with Robert Downey Jr. disproving the rumours that he was about to leave the iconic role but even if he does, War Machine or his wife Pepper Potts could be a sufficient replacement. Mandarin has alien rings of power so he might know better than Thanos to use foreign power to serve his own ends and adapting it so that it could combined with his own abilities, so he could possibly be the one to end the destructive path of Thanos and start his own. Mandarin has also been referenced in the TV series so it is only a matter of time before he is introduced.

Ant-Man

The hero who can shrink his sizes so much that he can be invisible to the naked eye has been well received by fans but has still not established himself as a hero of the same magnitude as his teammates, while his absence in Avengers 3 was both disappointing and mysterious, but he appeared in the trailer of Avengers 4 so we know for sure that he has an important role to play. What if the arrogance of Thanos or his distraction by the rest of the Avengers are enough for Ant-Man to climb upon his hand and destroy his Infinity Gauntlet as well as the Infinity Stones on it while being too small to use them for himself, therefore not being a threat in terms of being tempted by the gauntlet's power to abuse it?

Venom

Venom has surprisingly been a huge success at the box office and considering Tom Hardy's appeal being proven before in the DC masterpiece The Dark Knight Rises, the third entry of the acclaimed Batman film series that premiered on the same year as the first Avengers film, Venom's abilities that resemble those of Spider-Man, who despite being much weaker annoyed Thanos to such a degree that he called him an insect even if he did not know his name was based on an actual insect, might be enough to bring a huge twist in Avengers 4, with Venom using his webbing generation to snatch the Infinity Gauntlet from the hand of an ambushed Thanos while the Mad Titan is distracted from his fight with the other superheroes, but Venom's lack of knowledge over cosmic power and friendships with other characters who might understand it as well his deep hatred over Spider-Man that was referenced in the Venom film as he was the one responsible for Venom losing his job and getting into all the trouble shown in the movie since he moved from his native New York to San Francisco, would discourage him from abusing the power of the Infinity Stones and instead prompt him to revert the deaths of half the universe's population which included Spider-Man and then destroy the Infinity Stones to prevent Spider-Man's friends from using them to protect the iconic hero from the revenge that Venom wants to deliver personally.

Leader

Unlike his three teammates, Iron Man, Thor and Captain America, Hulk who alongside them is one of the four most popular Marvel heroes (excluding Spider-Man and Wolverine who are more involved in solo storylines or in Wolverine's case, the X-Men, instead of being members of the Avengers for the majority of the time instead of not so many occasions which is the case), has not been featured in three solo films but only got one which was the second in the entire franchise. A way to solve this problem would be to offer him the honor of being the one who puts Thanos down for good but because of the fact that this would make him too powerful to relate with the rest of the Avengers, Leader, who has been introduced as Mr Blue in The Incredible Hulk movie, could use the superhuman intelligence he got at the end of the film to predict everything that Thanos does and even personally defeat him even if he is lacking other powers that he did not need to cause lots of trouble upon the Hulk despite the latter's amazing strength as well as genius intellect as Banner rivaling Iron Man's.

Red Hulk

Thaddeus Ross, the general who has been known in the comics to be constantly hunting the Hulk before becoming a red version of him, has become the Secretary of State in the movies and was sidelined just like the rest of the Hulk-related characters, including his daughter Betty who despite being Banner's long love interest and later wife in the comics as well as the only solo film, she has disappeared ever since with Black Widow replacing her in a controversial plot twist, so how about movies reflecting real life, and the replacement of popular President Barack Obama by the disgraceful Donald Trump also happening in the movies, with the successor of the US President whose life was saved in Iron Man 3 sacking Thaddeus Ross just like Donald Trump usually does with many people leaving the former general angry about not being given a chance to defeat Thanos, angry enough to become the Red Hulk and personally take him down just like he wanted to do so with Hulk, whose beatdown from Thanos proved that Rulk should fear Thanos as much as he always feared Hulk, if not more?

Enchantress

The self-serving villain who despite her evil deeds actually wants to impress Thor in order to convince him to marry her and become her husband, has been a female version of Loki who despite lacking in physical combat, her sorcery manipulative skills have rivaled Loki's and challenged the great power of Thor. Therefore if Hela, who unlike the Enchantress has shown great physical strength, and Loki are supposed to stay dead, Enchantress who is not as evil as Hela could not only be a replacement of Loki and Hela as Thor's main villain, with her pawn Skurge already being introduced in Thor 3, but also a powerful female character rivaling Wonder Woman from DC that due to her role as a villain could not undermine the power of Marvel superheroes, unlike Captain Marvel who is a regular member of the Avengers as well as a recently empowered alias of Miss Marvel who had been much weaker, as she is involved in storylines of Thor who is the strongest Avenger alongside the Hulk, who has been manipulated by Enchantress despite the failure of many telepaths to do that.