Avengers: Age of Ultron: Vision is the Good Counterpart to Ultron. Both of them were designed to be extremely powerful Artificial Intelligences by their creators, were created using the Mind Stone, and ultimately went against their creator's designs (Ultron was meant by Tony to protect the world, while The Vision was supposed to be Ultron's final body). The main difference is that while Ultron looked at the world and saw only chaos and destruction, The Vision saw life, something that the two even acknowledge at the end of the film, right before Ultron commits Suicide by Cop.
In Avengers: Infinity War, thanks to the villains (the Black Order) being composed of five members, certain members serve as counterparts to the Avengers:
Cull Obsidian is this for The Hulk, being the Dumb Muscle for their respective groups; Cull is the The Brute for the Black Order and Hulk is The Big Guy for the Avengers. Both are capable of great savagery and destruction, though Hulk has a softer side being childlike and cares for his allies, while Obsidian Cull is little more than a snarling monster showing none of the humanity the Hulk has. It's due to being a dumb monster that Hulk's alter ego Bruce Banner can trick and kill Cull.
Ebony Maw is the evil counterpart for Doctor Strange, who is The Smart Guy while Maw is the Evil Genius. Both have special powers despite not possessing any superior physical strength. Maw also has a similar level of arrogance and surgical precision that Strange once had, though Strange healed people while Maw tortures people; and both characters are willingly to sacrifice their allies to achieve their goals. However, while Ebony Maw was fine with abandoning his brother Obsidian Cull on Earth, Strange on the other hand ultimately couldn't let Iron Man be killed by Thanos. Word of God makes it even more apparent revealing that Ebony Maw is actually a sorcerer like Strange is, though an evil one.
Corvus Glavie and Proxima Midnight are this for Battle Couple Vision and Wanda Maximoff aka Scarlet Witch. Aside from minor details like two of them wearing a cape, both couples fiercely love each other, with Vision and Wanda being a burgeoning couple and Corvious Glavie and Proxima Midnight a married one. Glaive and Midnight also respectively taunt Wanda and Vision about being unable to protect each other, but the Black Order couple are beaten at their own game as Glaive is ironically killed by Vision who stabs him in the back with his own spear and Scarlet Witch telekineticaly throws Proxima Midnight into one of her own bladed war machines. There's also the fact both couples were Together in Death (Wanda gets better, though).
Proxima is also the evil counterpart to Gamora and Nebula as, unlike her sisters, she is the only daughter of Thanos who never opposes him and believes in his lunatic ideals, while also possessing the same killing intent of her adoptive sisters.
Then there's Thanos, who is the counterpart to Tony Stark a.k.a. Iron Man, which is surprising but there was Foreshadowing. In many ways, they're the two characters in the MCU who are most symbolically connected as, according to Joe Russo, both Tony and Thanos are "Futurists", they see the end goal and willingly do anything for what they perceive is for the greater good, which is further helped by the fact that Tony is the first hero of the franchise, while Thanos is the Big Bad of the franchise. They are further entwined by both using technology in battle, being the father figure for their respective sides especially for Spider-Man/Gamora, and Tony is also the only character that Thanos addresses by name seeing "Stark" as another individual who is "burdened by knowledge", and therefore he respects him. That said, where Thanos and Iron Man differ is in conviction: Tony continuously learns from his mistakes, while Thanos is unwaveringly committed to his cause and only vaguely regrets his decision after he's lost everything — i.e sacrificed half the universe and Gamora —. Avengers: Endgame hammers the point home as not only do both Tony and Thanos exploit Time Travel to ensure victory, but Tony actually gives Thanos a taste of his own medicine and uses the Infinity Gauntlet (just like Thanos did) to wipe the latter from existence along with all Thanos’s forces, which of course serves as Laser-Guided Karma for Thanos’s actions in the previous movie.
Iron Man: Obadiah Stane/Iron Monger in is Tony's trusted friend and business partner. However, while Tony has a moral awakening and decides to stop selling weapons, Stane has no such hangups, and wants to continue. He ends up building his own version of Tony's Iron Man suit, which he plans to mass-produce and revolutionize warfare across the globe.
Iron Man 2: Ivan Vanko a.k.a. Whiplash in is just as smart as Tony, and his father helped Tony's father build the first ARC reactor. Growing up in a Soviet gulag can't be good for one's personality. He ends up building his first portable ARC reactor in his rundown apartment. With his own box of scraps.
Both Justin Hammer (Iron Man 2) and Aldrich Killian (Iron Man 3) are played as "wannabe" Tony Starks who aspire to and try molding themselves after him to some degree. Both are, or become, powerful businessmen like Stark, and similarly to how Stark started out both are self-centered.
The antagonist Emil Blonsky progressively starts injecting his body with substances to increase his physical capabilities. By the end, he has Samuel Sterns inject a compound made from Bruce's blood into his body which transforms him into the Abomination, which in terms of size and strength is very much an evil counterpart to the Hulk. Blonsky also similarly becomes more aggressive as a result of his transformation. Blonsky's desire to use the chemicals to become stronger is antithetical to the way Bruce desperately wishes to rid himself of the Hulk.
It could also be said that, whilst The Abomination serves as an Anti-Hulk, Samuel Sterns was played as an Anti-Bruce Banner. Both were great scientists who worked on a project to improve the resilience and capabilities of the human body, both of which eventually led to their transformations. Like Blonsky, Sterns also has a markedly more positive view of the Hulk than Banner, even referring to it as "beautiful" at one point.
Loki is this for the titular hero being his brother and Foil. Both princes are told from a young age that they're born to be kings, but only one of them can inherit the throne which they were both raised to desire. In Thor, both brothers initially have a similar mindset: Thor is just as power hungry as Loki but, unlike his younger brother, he is open about his vain desire, which leads to him attacking the Ice Giants and Odin to depowering and banishing him to Earth as punishment. Loki makes use of the opportunity to seize the throne when Odin falls into the Odinsleep and, like Thor, attacks the Ice Giants though Loki means to annihilate them so he can prove himself to Odin. By the end, Thor has learned from his mistakes and became a better person for it, while Loki took much longer to lose his malicious nature. By Ragnarok, their roles as counterparts have merged, as Thor like Loki becomes more mischievous and scheming, and Loki like Thor becomes more selfless and even heroic.
Loki is also this to Frigga. They're linked through their sorcery and trickery, which contrasts Thor and Odin's upfront combat attitude. Frigga is happy being the Queen consort of Asgard with a supporting role in her husband's reign, whereas Loki is miserable having to play second fiddle to Thor, the Crown Prince. Loki's envy and resentment towards his brother eventually lead him to commit fratricide (although the enchantment Odin had placed on Mjölnir revives Thor), while Frigga is devoted to Odin and protects him from Laufey's mook.
Thor: Ragnarok: Hela is this to both Thor and Loki, her younger brothers.
For Thor, he is actually biologically related to Hela and thus both have a claim to the throne; but Thor dropped his arrogance after the first movie and could see the corrupting effect of the throne, while Hela is proud of her world spanning-bloodshed. In the climax of the movie, Thor reflects that Odin made them both him and Hela believe they were worthy of ruling Asgard at, which Hela claims they’ve both been lied to. Thor was also cast out like Hela, but returned after his Heroic Sacrifice; Hela returned once Odin had died to rule and conquer (similar to pre-Ragnarok Loki), while Thor only accepts the throne when his people truly need him.
Hela's parallels to Loki are very apparent. Both wear green, have black hair, horny helmets and demand that people kneel before them. But while Loki eventually changed his ways, Hela stays a vicious Blood Knight to the end.
Captain America: The Winter Soldier: The Winter Soldier has many similarities to the Captain himself; both are soldiers, both have been empowered with science and both operate under orders of a larger organization (technically the same organization, as it turns out). Furthermore, both fought in World War II in the same unit but were cryogenically frozen (though Captain America stayed conscious after being revived, but the Winter Soldier was thawed and re-frozen as he was needed).
Nebula is this for Gamora. Both are the rebel daughters of Thanos who were both raised to be ruthless killers, and both received cybernetic upgrades to boot. However, Gamora always secretly strove to be a good person and became one thanks to her friends, while Nebula is disgusted by tender emotion and remains a Anti-Hero until later movies. Nebula gets an Evil Twin in her past self in Avengers: Endgame, who quite literally represents what Nebula would be without her Character Development.
Guardians of the Galaxy Vol. 2: Ego is this for his own son Peter/Star-Lord. Both are bearded charismatic goofy humanoid celestials who sleep with a lot of alien women, (pretty much to Extreme Omnisexual levels). Also, they both have a love of 80s music which they get from Meredith (Peter's mom), but Ego ultimately sees no value in love preaching to Peter and believes that as gods they transcend such petty emotions, which goes against everything Peter believes; not to mention that Ego killed Meredith so she would no longer distract him which sets Peter off. Their connection and contrast become greater when Peter taps into the celestial power and fights his father but, unlike Ego, he has capacity to give up his god powers.
Ego: Listen to me! You are a god! If you kill me, you'll be just like everybody else!
Ego has parallels with Yondu as well, since both have committed many crimes and both are father figures to Starlord; but while Yondu truly loved and cared for Peter, Ego saw him as a Living Battery, which led to Yondu protecting Peter from Ego by keeping him from the Celestial. Yondu lampshades this:
Yondu: He may have been your father, boy, but he wasn't your daddy.
Darren Cross is one to Scott Lang. Both men were recruited by Hank Pym, but while Scott becomes a hero and uses his skills to help people, Darren double-crosses Hank and hijacks his company. The Yellowjacket armor Darren wears is also effectively a much more advanced (and sinister) revamp of the Ant-Man suit worn by Scott. Funny enough, Edgar Wright says the idea to use an evil version of Ant-Man as the Big Bad was actually inspired by the Iron Man example above.
Darren is also one to Hope. Both hold a grudge against Hank by the start of the movie, but while Hope managed to reconcile with her father, Darren does not and wants to prove himself better than Hank.
Ant-Man and the Wasp: Ava Starr a.k.a. Ghost is another evil counterpart to Hope. Both women are quite merciless, but conversely both love their parents dearly; and they have respective reasons for wanting to reach subatomic world parallel but differ their in goals, with Hope wanting to reach her mother Janet and Ava more selfishly wanting to cure her Intangibility (even at the potential cost of Janet's life). Ava's relationship with Bill Foster also reflects Hope's relationship with her father Hank.
Adrian Toomes a.k.a. The Vulture is evil counterpart to the titular Wall Crawler. Both are tech-savvy, disconnected with authority and have underlying care for their loved ones. However, Vulture's greed is countered by Spidey's utter selflessness, as Spidey gives up opportunities for self gain and happiness three times, while avid avarice nearly costs Toomes his life in the ending.
Phineas "The Tinkerer" Mason to Ned Leeds. Both are overweight nerdy guys and loyal friends who encourage their more powerful friends to go on dangerous missions. This is most notable in the climax where both Ned and Mason serve as "the chair guy" to Peter and Toomes.
The person leading the Elementals in Spider-Man: Far From Home is of course another evil counterpart to MCU Spidey. Specifically, Quentin Beck (a.k.a. Mysterio) reflects how Spider-Man was in Homecoming: an insecure Heroic Wannabe desperate to be an Avenger to the point of endangering innocent lives due to their actions. However, while Peter sobered over the events of Infinity War and Endgame, Mysterio is largely apathetic to the consequences and responsibility of his actions. In fact, unlike Spidey, Beck thinks collateral damage will benefit him and give him more coverage. Also, Mysterio and Spidey both actively lied to people, though Peter did it to protect his loved ones, while Mysterio was just bullshitting for the sake of personal gain.
Norman Osborn (a.k.a. Green Goblin) in Spider-Man: No Way Home is a evil counterpart to Iron Man. Both are wealthy and capable scientists who rely heavily on technology in combat while also playing a major role in Peter's life. However, whereas Tony acted as a surrogate father and encouraged MCU Peter to become selfless, the Green Goblin tries his best to corrupt Peter into becoming a selfish villain like him. He is also this for all versions of Spider-Man, believing that his powers gives him the right to do whatever he wants in contrast to Spider-Man's core philosophy that great power comes with great responsibility.
The main antagonist of the film, Kaecilius, like Strange, is a former pupil of the Ancient One. Unlike Strange, he turned to evil in order to gain forbidden knowledge.
Jonathan Pangborn is a neutral counterpart to Strange, having turned to the magic arts to heal his crippling injury; but unlike Strange, Pangborn did not pursue learning magic, instead selfishly leaving once magic had healed his spine. Strange, however, learned his lesson and didn't heal his hands, knowing it was his arrogance that led to him crippling them in the first place.
Ultimately, Karl Mordo becomes Strange's main evil counterpart, being another former pupil of the Ancient One; but over the course of the movie, Mordo becomes disillusioned with magic, while Strange becomes enlightened.
Black Panther (2018) has one of the most effective examples in the form of Erik "Killmonger" Stevens, a revolutionary who opposes King T'Challa and wants to take over Wakanda. In his attempted coup, Erik ingests the Heart-Shaped Herb, which grants him all of T'Challa's powers, and then dons his own golden version of the vibranium Black Panther suit.
Taskmaster aka Antonia Dreykov and the rest of the Black Widows serves as a bad counterpart to Natasha, being rutheless assassins who remain loyal to Black Widow whlist Nat was able to escape. Subverted though as they are Brainwashed and Crazy thanks to Dreykov's chemicals and join the good guys once Nat and co free them.
Played straight with Dreykov being Alexei's Evil Counterpart. Both are/were proud agents of Soviet Armed Forces and are porty in apperance and are secrety insecure, both raised Natasha and Yelena and have an attraction to Melina (though it's not consenual in Dreykov's case). Alexei however at heart is a good man whom geuinely loves and caresfor his surrogate wife and daughters despite being unrelated by blood to them whereas Dreykov is an abusive father to the girls of the Red Room and turned his biological daughter into the souless Taskmaster.
Live-Action TV
In Agent Carter, Dottie is this for Peggy. Both she and Peggy are secret agents, as well as skilled Action Girls. They both use other people's underestimations of their skill to their advantage. Peggy does this by using her coworkers' sexist assumptions about her abilities while Dottie does this by Obfuscating Stupidity and acting like a ditzy Country Mouse. Both are capable of flawless American Accents when undercover. They are also both Only Known by Their Nickname. But they use different fighting styles, with Dottie relying on She-Fu acrobatics, whereas Peggy relies on her fists, Improvised Weapons, and brute force. Additionally, Peggy chose to become a secret agent, while Dottie was Brainwashed into becoming a Child Soldier at a young age by her Russian trainers.
More like Anti-Hero Counterpart, but The Punisher from Season 2 serves as this to Daredevil. He's a violent vigilante motivated by the traumatic death of his loved ones, but unlike Matt, who never kills, the Punisher is an unrepentant murderer who has no moral hangups about slaughtering criminals. A good chunk of the first half of the season focuses on the idealogical conflict between the two vigilantes, as well as the many ways they mirror one another.
Season 3 has Benjamin "Dex" Poindexter, A.K.A. Bullseye. Like Daredevil, he was an orphan, is a tremendously gifted athlete and fighter who possesses special skills, and is effectively a One-Man Army. Even his severeParental Issues (particularly his fear of abandonment and the way he views Fisk as a surrogate father figure) parallel Matt's own bitterness over having been abandoned by his mother. However, while Matt is strongly opposed to using lethal force, Dex is a violent Sadist who actively enjoys killing people. To further the parallels, Dex spends a good portion of the season impersonating Daredevil by using a replica of Matt's costume.
After The Reveal in Episode 7, Agatha Harkness serves as the Evil Counterpart to Wanda. Both are powerful sorceresses who have been victimised and made poor choices in the pursuit of empowerment which led to both of them to descend into villainy. Except Wanda found a Morality Chain in the Avengers namely Vision who brought the goodness out of her while Agatha beneath her bubbly persona is cruel and Would Hurt A Child Level-psychotic with no regard for others besides herself (and her demonic bunny rabbit). The way they use magic is polar opposite too, Agatha uses The Dark Arts to manipulate, bind, hurt and outright drain the life out of people. Wanda conversely uses her one of a kind Chaos Magic to resurrect her husband, give herself children and turn a depressing small town into a cheerful one to the astonished disgust of Agatha. How they respond to fair persecution is opposite as well, Agatha kills her coven when they try and bring her to justice whereas Wanda when faced with the consequences of what she did to the people of Westview, while she reacts violently at first ultimately lets them go and apologises .
The Stinger of Episode 8 reveals White Vision who is the parts of the original Vision Reforged into a Minion by General Ripper Hayward. Unlike the Vision we know, White Vision is cold and inhuman and in Episode 9 almost kills Wanda before being stopped by his Good Counterpart (who comes from the part of the Mind Stone that lives in Wanda and her good memories of Vision). Subverted though as White Vision deep down is not a heartless and violent machine like Ultron and through a Battle of Wits and by unlocking his counterparts’s memories Vision is able to restore humanity to his “real” and physical self. Wanda’s Vision also points out to White Vision that they’re not all that different, being echoes of one dead synthezoid brought back to life.
While they don't meet in the series, John Walker is a bad counterpart to Steve Rogers like the comics. Both are blond, well-meaning, courageous, headstrong idealistic men with a loyal dark-haired wife, have Determinator attitude, lose their best friends and come into conflict with their allies. The difference is that John is a new society-version of Steve serving the USA army against Afghanistan in The War on Terror which is much more morally grey than the black and white backdrop of World War II which Steve grew up in. John thanks to his time in Afghanistan has severe PTSD and forcing to live up Cap's legacy has a Sanity Slippage taking a Super Serum out of desperation instead of volunteering for it like Steve did. Also where Steve could own up to his mistakes and drops the shield after bludgeoning Tony with it, understanding his actions had made him unworthy of it John in a similar situation (except the bludgeoning was lethal) holds onto the shield proudly and refuses to give it up. This forces Sam and Bucky to take him down.
John also serves a counterpart to Sam. Both are military vets who lost/lose their partners on a mission and are faced with the prospect of carrying on the legacy of Captain America and go about in different ways. John uses forceful tactics, Police Brutality and is willingly to mercilessly kill his foes. Sam on other hand accepting the flaws and hypocrisy of his country and the Captain America title, decides to be a Hope Bringer and call the GRC out for their actions that led to the creation of Flag Smashers. Unlike John, Sam is a Martial Pacifist as Captain America taking mercy upon Batroc and Flag Smashers and tries to talk Big Bad Karli Morgenthau down.
Bucky finds a evil counterpart in Sharon Carter. Both have been left behind by Steve their closest ally and are greatly heartbroken without him, but deal with the feelings over it in vastly different ways. Bucky learns to put the past behind him to the point of deliberately refusing to kill Zemo and accepts flaws of Steve's legacy but supports Sam as the new Captain America regardless. Sharon in contrast felt abandoned after the events of Captain America: Civil War as Team Cap never came back for her, considering Steve's philosophy a Broken Pedestal she pulled a Face–Heel Turn and became the Power Broker. While Bucky manages rid himself of the darkness inside him, Sharon embraces it.
Sharon as the Power Broker is also the antithesis of everything her great aunt Peggy stood for.
Loki has a several counterparts more or less reprehensible than himself. President Loki and Boastful Loki representing what he would be like without his Character Development i.e a Smug Snake with Chronic Backstabbing Disorder, while Classic Loki and to a lesser extent Kid Loki show his potential for goodness and heroism with Classic Loki performing a Heroic Sacrifice. Sylvie, Loki's Distaff Counterpart zigzags this at first she's set up as the "badder" counterpart him, until it's revealed the TVA is corrupt and Sylvie is Chaotic Good in wanting to bring them down. Then at the end when faced with the person who has ruined their life to maintain a Stable Time Loop, becomes a real bad counterpart as Sylvie unlike Loki refuses to listen to reason (having spent her life without any guidance or compassion from others) betrays Loki and kills He Who Remains/Immortus seemingly dooming the entire multiverse.
Renslayer ultimately becomes the evil counterpart to Mobius. Both are bureaucratic agents of the TVA who maintain the rules to a fault and are close colleagues. Then Mobius learns the truth that they are all variants whom have been stolen from their timelines and defects while Renslayer (who knows the truth) continues to uphold the laws of the TVA and prune anyone who rebels.
Played with in regards to He Who Remains. While a insane jerkass who put trillions of lives in slavery to maintain the sacred timeline and destroy anything that threatens it, turns out he's actually the Good Counterpart to his Evil Counterpart Kang the Conqueror and many others whom he has been keeping in check. After Sylvie kills him, his counterparts start popping up all over the place.
Chaotic Good in wanting to bring them down. Then at the end when faced with the person who has ruined their life to maintain a Stable Time Loop, becomes a real bad counterpart as Sylvie unlike Loki refuses to listen to reason (having spent her life without any guidance or compassion from others) betrays Loki and kills He Who Remains/Immortus seemingly dooming the entire multiverse.