Audiences worship heroes, especially when they're of a superpowered nature. They have a love and respect for superheroes of all kinds and see them as the foil to the worst evils imaginable. That being said, there are times when the heroes can have villainous actions.
The MCU, the now legendary cinematic universe, offers up such scenarios, showcasing heroes and villains sometimes switching roles. There are times when heroes can be villainous and when villains can come across as heroic. It's these times when characters of all kinds can be the most interesting and fascinating of almost all other forms of characters.
Villainous: Hawkeye Becomes Ronin
When someone's world ends, how does that person change? The world in question happens to be Clint Barton/Hawkeye's when his entire family is dusted before his eyes by the Snap. In grief, Clint ventures out, becoming Ronin and slaughtering the criminals left behind.
Driven by rage and grief, perhaps Clint's actions shouldn't be looked on too harshly. Still, his violent and vicious rampage through the criminal underworld goes against who he was. Hawkeye was precise and accurate, only killing when need be. Ronin was the exact opposite, taking lives at will.
Heroic: Loki's Sacrifice
Now, one could almost consider Loki, the trickster God, first foe of the Avengers, and most powerful villain of Phase 1, an anti-hero at this point. Still, given his checkered past, the life of a villain is the one Loki leads in one form or another, even when he gives his life for Thor.
After being attacked by the Mad Titan Thanos, demanding the Space Stone and nearly killing Thor for it, Loki gives the stone up, allowing for his brother to be spared even as he's killed by the hand of Thanos.
Villainous: Star-Lord Attacks Thanos
At the climax of mighty and powerful Thanos on the ropes. On Titan, the mix of Avengers and Guardians were moments away from getting the gauntlet off... right up until Star-Lord lashed out in anger after hearing of Gamora's demise.
Some fans see this as Star-Lord acting out of anger and shock. It's a human thing that anyone could've done. But it could be said that Star-Lord didn't try and stop himself or pull back, leading to his outburst becoming an act of selfishness that led to the heroes losing.
Heroic: Vulture's Gain
If there's one thing fans can thank the MCU for doing, it's for making The Vulture, one of Spider-Man's first villains, an interesting character. In comics, Vulture's nothing more than an old thief flying around in a bright green suit.
However, all Adrian Toomes, Toomes again with the Spider-Man movie.
Villainous: Tony And The Accords
One of the biggest divides in the entirety of the MCU is the Sokovia Accords. So many audiences have one feeling or another on them. A fair amount disagrees with the Accords. Others, like Tony Stark, agree and try to enforce them to mixed results.
Tony siding with Ross and working to make the Accords a larger part of the US and the Avengers was the whole reason for Civil War. It tore the team apart and forced them against one another. If Tony had sided with Steve, things may have been different.
Heroic: Zemo Tore The Avengers Apart
Of course, Tony wasn't the only man to break the Avengers. Baron Zemo, a distraught father who lost his entire family in Sokovia, sought revenge against the Avengers, leading to the death of innocents all to tear the Avengers apart. A villainous act... from a certain point of view.
The thing with villains is to look at the world from their eyes. In Zemo's eyes, he was the hero of the story, tearing down the almighty Avengers to avenge his family. The act itself wasn't heroic but doing something in the name of your fallen family could be viewed as heroic in the eyes of the person who pulled it off.
Villainous: Wanda Traps Westview
Grief isn't an easy road to travel upon and it can drive people to do terrible deeds. After losing her family, her brother, causing the death of innocents, and watching her lover Vision die twice, Wanda Maximoff was on the verge of breaking down.
And in rewrote it to be her own sitcom to grow old with Vision, using the residents as human puppets, constantly in pain. As said before, grief can lead to terrible deeds.
Heroic: Thanos "Saves" The Universe
Again, seeing the world through the lens of a villain is an interesting concept. It opens the audience up to the possibility of an antagonist like Thanos, the big bad of the MCU, to actually be a protagonist.
Now, Thanos killing half the universe isn't a good thing. Yet, it could be argued that there was some mercy to his actions. He could've easily wiped out all life, as shown by his 2014 counterpart. In his eyes he was right and his actions were indeed completely random, which was somewhat fair.
Villainous: Tony and Bruce Create Ultron
There are times when the best of intentions can lead to the worst consequences. After retrieving Loki's staff in Age Of Ultron, Tony convinced Bruce to help him build a suit of armor around the world, to create "peace in our time."
Yet, by doing so, the pair created Ultron, who developed a God complex and decided to wipe out all of humanity after spending five minutes on the internet. While not intentional, Bruce and Tony should still be held able for their somewhat vile and villainous actions.
Heroic: Killmonger Exposes Wakanda's Hypocrisy
What if the villain is right? That's the question most writers should ask themselves when trying to create a good bad guy. How can one show that a villain's intentions are correct and they're not the ones at fault? The answer for the MCU: Killmonger.
Returning to Wakanda to take back the throne, Killmonger challenges the hidden nation's beliefs, stating that for all their technology and achievements, they've done nothing for the world. The way he goes about this is entirely wrong but Killmonger still convinces T'Challa to open Wakanda up to the world, strengthing his point.