Thanos is a fictional character and the main antagonist of the Marvel Cinematic Universe.
He served as the overarching antagonist in both The Avengers and Guardians of the Galaxy before making a cameo appearance at the mid-credits in Avengers: Age of Ultron. He then appeared as the primary antagonist in Avengers: Infinity War and is set to reprise that role in the untitled 2019 Avengers sequel.
Thanos was born on a planet called Titan to an unnamed species of large purple life-forms, which was nearing destruction to overpopulation and rapid depletion of resources taking place at the time. Desiring to do something about it, as he deeply cared for his people even though he was viewed as a deformed freak by the rest of his species, he made a proposal to the Titan government that they exterminate half the planet's population so the other could survive. However, they all rejected this idea and called him mad for this. Not too long after, Thanos' species went extinct. Being the only known survivor, Thanos started looking throughout the universe for "balance", but everywhere he went had something wrong with it (at least in his eyes); he took the title of "Mad Titan" and started going planet-to-planet, wiping out half of it to save the other half. In his mind, if life was spreading throughout the universe unchecked, it would bring ruin.
Among the species he wiped out was the Zehoberei, a species of green humanoids, and took in the last known survivor Gamora, raising her as his daughter. Also taken in was Nebula, a blue humanoid from another world he visited and had both of them given cybernetic implants. Both Nebula and Gamora had a sibling rivalry but became attached, with Nebula saying "of all our siblings, I hated you the least", suggesting that there were many other siblings. Thanos once calls Gamora "my favorite daughter" without considering Nebula being present at the moment. In their childhood, they would fight a lot, and Thanos would force a cybernetic enhancement on the loser. Each and every time, Nebula would lose and her body became less and less organic. At some point, he took command of the Chitauri species and used their leader The Other as an emissary.
He eventually learned of a way to bring "balance" to the entire universe all at once: the Infinity Stones of immeasurable power. Using a golden gauntlet called the "Infinity Gauntlet", he sought to attach all the Stones to it and wipe out half the universe's populace with the snap of his fingers. At some point, he obtained the Mind Stone (which could mind-control people) and put it into a Chitauri scepter of his making while the other Stones eluded him.
In the film, Thanos appears in a post-credits scene, where the Other tells Thanos that the Tesseract, the Space Stone, is on a small world, a human world. It also informs him that Loki is ready to lead the Chitauri, and so he was given the scepter with the Mind Stone to get the Tesseract. In a post-credits scene, Thanos is revealed to have been Loki's benefactor, having provided the Chitauri Army and the Mind Stone inside Loki's scepter used by Loki in his attempted invasion of Earth. When advised by the Other that opposing the Avengers would be "to court death", as the human race was not as weak as Loki claimed, Thanos glances at the camera and flashes an evil grin.
GUARDIANS OF THE GALAXY
Thanos plays a more active role in the film, where he has enlisted the help of Ronan, Korath, and his daughters, Gamora and Nebula, to retrieve the Orb (Power Stone) for him. As it turns out, Gamora is not actually Thanos's daughter, since Thanos killed Gamora's family and snatched her as an infant to train her into the perfect assassin, having abused and tormented her in the process of doing so. This causes Gamora to betray Thanos, which leads to a chain of events that leads to Gamora finding her true calling as a protector of the universe and a member of the Guardians of the Galaxy.
When Ronan and Nebula are called to discuss Gamora's betrayal, Ronan kills The Other, who was speaking for Thanos. Thanos does not react to this but is furious at Ronan for not obtaining the Orb (and for apparently alienating Gamora).
After berating Ronan and calling him "Boy", Thanos says he will destroy Xandar for Ronan if he brings him the Orb but promises to "bathe the star-ways with [his] blood" should he fail him. Nebula then easily persuaded the frightened Ronan to leave, as they knew too well he is no match for Thanos.
Thanos promised Ronan that he will help Ronan destroy Xandar in exchange for Ronan's services. However, once Ronan gets a hold of the Orb, he feels he no longer needs Thanos help and also decides to betray him. Nebula also decides to betray Thanos out of jealousy over Thanos showing a preference for Gamora over her. Ronan and Nebula take Korath with them, while Thanos, unfazed by their threats of killing him, cut off contact with them in anger of their betrayal.
In the end, Ronan and Korath are killed by the Guardians of the Galaxy (including Gamora), Nebula escapes and becomes a renegade villain independent of Thanos, and the Guardians give the Orb to the Nova Corps for safekeeping. Drax the Destroyer, who got revenge on Ronan for killing his family, decides to turn his attention to Thanos, as the latter was the one who sent Ronan to kill Drax's family.
However, Thanos is still determined to find the six Infinity Stones and the Infinity Gauntlet so he can use them to conquer and rebalance the universe and this event would finally make him decide to come out to the open.
AGE OF ULTRON
Thanos is indirectly mentioned numerous times in this film; the first time was when Tony said of a possibility that a powerful villain would destroy the Avengers, which made Thor finally realize that someone has been manipulating the events (including Loki) to find the Infinity Stones. This was foreshadowed when Tony and Banner found Loki's scepter and used it to bring life to a peacekeeping A.I. program, which later became known as the homicidal cyborg Ultron, much to both Tony and Banner's distraught.
Gaining sentience from the power of the Mind Stone after breaking the scepter and killing HYDRA leader Wolfgang von Strucker, Ultron decides to utilize the Mind Stone in his plot to destroy the Avengers and all of humanity with his own army of Ultron Sentinels. Tony also suffered a nightmare (thanks to the powers of Scarlet Witch) where he sees all the Avengers being murdered (presumably by Thanos) while more Leviathans are heading towards Earth, foreshadowing Thanos' plot to take over the universe with the Infinity Stones.
Eventually, as Ultron and his Sentinels end up being destroyed by the Avengers at Sokovia while the Mind Stone ends up in the possession of Vision, Thanos finally appeared in a mid-credits scene, where he is fed up with losing his resources and his henchmen failing him and betraying him in his failed attempts to acquire the Stones. He goes into a white room in an unknown location and takes the Infinity Gauntlet from its hiding place, swearing to collect all of the six Infinity Stones (including the Mind Stone) by himself.
GUARDIANS OF THE GALAXY: VOLUME 2
Thanos doesn't appear in the film, but is mentioned twice, once by Nebula (who angrily blames Gamora for the lifetime of pain and misery that she suffered at the hands of Thanos), and another by one of the Ravagers (led by Taserface) as he is aware that Nebula is Thanos' adoptive daughter. Eventually, after having a change of heart and helping the Guardians defeat Ego and the Sovereign, Nebula reconciles with Gamora but leaves her as she intends to kill Thanos and prevent anyone else from falling under his control.
Thanos doesn't appear nor is mentioned in the film. However, his giant ship (the Sanctuary II) is seen during a mid-credits scene as it was intercepting one of the Grandmaster's giant ships containing the Asgardians survivors following the deaths of Hela and the Berserker Army, as well as the destruction of Asgard, by the hands of Surtur. It can be implied that Thanos and his forces are going after the Space Stone (the Tesseract) that Loki saved from Ragnarok following Surtur's death.
In the film, Thanos is first seen sending his elite team of adopted children (known as the Black Order) to attack the Asgardians' ship, being aware that Loki took hold of the Tesseract before Asgard's destruction. Thanos and the Black Order massacre Half of the Asgardians and he personally beats Thor up with ease. Thanos is surprised by Hulk but he easily defeats him. As all of the Asgardians are being slaughtered while the Hulk is sent back to Earth to warn of Thanos' arrival, Thanos coerces Loki into surrendering the Tesseract by threatening to kill a beaten Thor. Loki does so but intends to reclaim it back for Thor by feigning loyalty to Thanos in an attempt to stab him with a dagger. Unfortunately, Thanos easily anticipates this move and lifts Loki while choking him. Thanos calmly mocks Loki for saying undying fidelity and is unfazed when Loki says he will never be a god, snapping his neck in front of a horrified Thor. It was later revealed that Thanos has previously acquired the Orb after invading and destroying the planet Xandar, and he uses the Orb to destroy the Asgardians' ship, leaving a helpless Thor to drift in space.
With two of the Infinity Stones in his possession, Thanos sends the Black Order to Earth to collect the Time Stone (the Eye of Agamotto) and the Mind Stone while he travels to Knowhere, where he most likely kills the Collector to get hold of the Reality Stone (the Aether). Using the Aether, Thanos conjured an illusion that succeeded to lure the Guardians into a trap. He proceeds to easily capture Gamora and calmly uses the Reality Stone to turn Drax and Mantis into pieces. Thanos then forces her into giving out the location of the Soul Stone by threatening to torture and kill a captive Nebula. Having no choice, Gamora confesses that the Soul Stone is in the planet Vormir and is guarded by the Stonekeeper (previously known as Red Skull). Traveling to Vormir with a captive Gamora, Thanos is told by Red Skull that he will give the Soul Stone, but only if Thanos is willing to sacrifice a loved one. Gamora laughs at this before claiming that Thanos doesn't care for anyone, but Thanos turns to her revealing tears, as she is the only thing and the only adopted child he truly loved; even the Red Skull points out that the tears are for Gamora. Despite realizing this, Gamora tries to commit suicide to ensure that Thanos cannot get the Soul Stone, but Thanos foils this and reluctantly kills her by throwing her off a cliff to gain hold of the Soul Stone.
With four Infinity Stones in place, Thanos travels back to his homeworld Titan, where he intends to wait for Ebony Maw to deliver the Eye of Agamotto. However, he found Doctor Strange waiting for him and instantly deduced that Maw is dead due to Tony Stark (Iron Man) killing him to save Strange (the current holder of the Eye). Unfazed, Thanos explains his goals and begins a ferocious battle with the majority of the Guardians, who have arrived after being contacted by Nebula. Despite being outnumbered, Thanos proves to be too powerful to defeat easily and fights them off using the Gauntlet and his fighting skill and physical power effectively. However, Nebula arrives and although Thanos subdued her swiftly, the heroes barely managed to briefly subdue Thanos thanks to Nebula's distraction of Thanos. Despite this, Thanos still put up a fierce fight and eventually they learned that he has killed Gamora to get the Soul Stone, which provoked an angry Peter Quill to attack Thanos. Unfortunately, this breaks the heroes' group on Thanos, who then initiates the Guardians, forcing Spider-Man to save them from the oncoming meteor shower and making him unable to help Iron Man and Doctor Strange, before overpowering Strange's magic and severely injuring Iron Man, although Strange surrendered the Time Stone to him so he would spare Tony, a deal that Thanos agreed to.
Meanwhile, Corvus Glaive, Proxima Midnight and Cull Obsidian assemble a massive army of Outriders to attack Wakanda, being aware that the hero Vision has the Mind Stone lodged in his forehead and is currently located in Wakanda. This forces several Avengers and the Wakandan warriors to fight back against Thanos's army. At first, the heroes are being overwhelmed, but Thor, Rocket Raccoon and Groot arrived at the rescue with a new powerful weapon called Stormbreaker, allowing the Avengers and Wakandan warriors to finish off Glaive, Proxima, Obsidian and the Outriders to their defeat and deaths. However, Thanos personally arrived on Wakanda after acquiring the Time Stone and managed to easily defeat the Avengers and Guardians, only to witness Scarlet Witch removing the Mind Stone from Vision and destroying it with her powers. Unperturbed by this, Thanos used the Eye of Agamotto to reverse this event, allowing himself to collect the Mind Stone while killing Vision at the same time, much to Scarlet Witch's distraught.
In a last-minute attempt to finish off Thanos, Thor imbued all of his power, further fueled by his strong desire to avenge Loki and the Asgardians and stop Thanos from achieving his goal, into Stormbreaker and managed to violently strike Thanos in the chest before using all of his strength to twist the axe as deep as he could into Thanos. Despite being severely wounded by Stormbreaker, Thanos has already infused all the Stones into the Gauntlet and sends out a death wave with a snap of his fingers in retaliation, taunting Thor that he should've aimed for the head instead. As a result, half of the universe's populace starts to disintegrate away to their deaths (including several Wakandan warriors, Avengers and Guardians) while Thanos briefly enters into limbo, where he talks to a young Gamora about his successful goal, but not before tearfully admitting to her that it cost him everything he had (his armies and adoptive children). Despite the Gauntlet being damaged as a result, a victorious Thanos escapes away with it, and the surviving heroes are horrified that they lost and that the entire universe is now in disarray due to losing their families, friends and allies to Thanos' death wave. A fully recovered Thanos is last seen watching a sunrise from another planet with a smile on his face, satisfied that he finally defeated the heroes and achieved his goal.
AGENTS OF SHIELD
Thanos doesn't appear in the series, but he is mentioned in the Season 5 episode The One Who Will Save Us All, where Graviton learns from the Kree about Thanos' plot to wipe out half of the universe. As such, Graviton suggests that they ally with the Avengers to fight against Thanos, but the Kree convinced him to obtain more Gravitonium in order to absorb it and increase his powers.
ANT-MAN AND THE WASP
Thanos doesn't appear nor is mentioned in the film. However, during a mid-credits scene following the arrest of Sonny Burch and the curing of Ghost, it is revealed that Thanos' death wave has killed Hank Pym, along with his wife Janet van Dyne and their daughter Hope (known as Wasp), leaving them to be wiped away from existence. The Pym family's demise also caused Hope's partner Scott Lang (known as Ant-Man) to be left trapped in a quantum realm, much to his complete distraught.
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His hunger for power, despite already being among the most (if not the most) powerful beings in the universe, is evident by his searching for the Infinity Stones with the apparent goal of controlling all of existence. He desired to use the Tesseract to look beyond the known worlds to find greater ones that it would unveil. He is also extremely dangerous, bloodthirsty, sadistic, and cruel, finding children that he can raise to be assassins and forcing them to watch as he murders their families. He is also an exceptionally intimidating individual, easily striking fear into those who are his allies even if they hold considerable abilities and powers, with Ronan the Accuser showing visible signs of fear in his presence and Loki doing so at the mere mention of him, as well as being able to command the Chitauri army unchallenged.
Thanos is extremely unforgiving and intolerant of failures, with a loathsome nature; The Other warned Loki that he would know a new kind of pain if he did not give them the Tesseract, something which visibly scared the God of Mischief and made him more determined than ever out of fear of Thanos's power. Even though Thor had not yet known about Thanos, he could still sense Thanos's easy control over Loki as being absurd due to Loki's arrogance. This side of his was shown further when Thanos furiously threatened to bathe the stairways in Ronan's blood if he failed to deliver the Orb, something which scared one of the strongest Kree into submission, and forbade Gamora from rescuing Nebula when the latter fell into a trap whilst on a mission in the Cloud Tombs of Praxius. Strangely, while he did ruthlessly kill Loki for failing him and attempting to kill him, he did not torture Loki first, apparently deeming the God of Lies as not being worth his time due to being far more interested in his winning war for the Infinity Stones.
Thanos has little to no regard for his followers, even his adopted children, showing absolutely no empathy when Ronan killed The Other and referring to Gamora as his "favorite daughter", even with Nebula present. He remained calm even after learning of Maw's death and was not fazed by the death of all the Black Order, although given he said Maw did his mission anyway, it is implied he may feel gratitude for their loyalty and respects their efforts. While Thanos's charisma makes him able to inspire complete loyalty to most of his adopted siblings, he is not flawless in his ability to fake parental affection and to the children he dislikes, he inspires no love, as he is despised by his own "daughters", Gamora and Nebula. Thanos has proven to have absolutely no care for Nebula, as he had no qualms removing parts of her in order to make her stronger, taking her apart piece by piece and replacing her with artificial limbs and organs so she would be able to defeat her sister and always punishing her for failing. He even went as far as to cruelly and ruthlessly torture her and seems to have zero respect for her skills as a fighter, going as far as to say that he did not want to waste time killing her. However, Thanos is not completely unable to love. He quickly took intrest in Gamora after seeing her fight against her captor and decided to spare her and even went as far as to shield her from the massacre of the Zehobereis, teaching her on his views of balance. He grew to genuinely care for and deeply love Gamora as his child. Thanos held her abilities above all others and favored her above all of the other adopted childrens, to the point that he entrusted her to find the Soul Stone and was visibly disappointed by her lie. He notably did not torture her but instead Nebula to retrieve the Soul Stone. He was deeply saddened for having to kill her to get the Soul Stone and mourns and feels severe emotional pain for her death that Mantis was able to feel.
Thanos is also manipulative and hesitant to trust, sending Ronan to retrieve the Orb for him and not telling him that it contained an Infinity Stone. He keeps a low profile, lurking in the shadows and making others do his work for him. However, after both of his alliances backfired, he shows that he is fully capable of taking action himself, as he decided to hunt for the Infinity Stones himself.
Thanos is also highly confident to the point of borderline arrogance. He merely smiled when The Other told him challenging the Avengers is like courting Death. He even was unfazed when Ronan threatened to kill him with The Orb, despite knowing well that the Kree was already very powerful even without the Stone, displaying only anger over his betrayal. Thanos also confidently smiled when he decided to collect the Infinity Stones personally.
It has been revealed that Thanos once had a kinder and more benevolent side to himself, as he cared deeply for his planet and people even though he was shunned for being deformed, as he tried everything he could to convince the governments of his planet to do what he suggests. The fact that they were unable to understand his resolve to save his planet and called him insane permanently made him who he was in the present with his desire to exterminate half of the population of every planet so as to save these civilizations from the same overpopulation tragedy which destroyed his home planet. This is why Thanos truly believed his cause for killing off half of everyone in all planets to be a righteous cause, seeing himself a righteous soul who is doing what is necessary to save all the civilizations of the universe, so they do not face the same tragedy as his home planet.
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