From the Avengers movies to the X-Men, we have seen many villains with entirely different goals. Some only want to cause destruction and harm as many lives for no apparent reason. Other villains have distorted views of reality and truly want to make a difference, but just don't know how to go about it.
Some villains, such as Nebula from Guardians of the Galaxy, are simply minions that are following orders and wish for a better life. Fans have been given years' worth of content from Marvel movies with a different villain in each one, so which villains are the worst of the worst, and which could possibly be salvaged?
Redeemable: Magneto
Magneto may have taken plenty of extreme measures, but there's no hiding the fact that he was best friends with Charles Xavier and they once had similar goals.
Magneto wants mutants to be seen and acknowledged for who they are, rather than having to blend in and hide in society because they're powerful. In a way, he's not wrong, but his methods are severe. If Magneto was on Xavier's team before, it's likely he could be redeemed and join his old friend again.
Too Evil: Thanos
Unlike many other villains, Thanos wanted to become the most powerful being in the world, but for no legitimate reason. He caused so much havoc on every planet he's ever been to, he stole children from their parents and destroyed entire planets.
Thanos was also responsible for the snap that turned millions of people to dust, which separated many from their families. He did that for no entire reason except to cause destruction, which is why it's clear Thanos can never become a hero.
Redeemable: Killmonger
It's not hard to understand why Killmonger wanted to take the Black Panther's throne. T'challa's father was responsible for the death of Killmongers father, and he wanted to follow in his dad's footsteps.
Also, Killmonger's goals as a whole weren't all that bad, considering he planned to share Wakanda's technology with Africa and end all oppression in the country. His techniques and lack of care for human life are what put him in the villain category, but if things were slightly different he might have been a great hero.
Too Evil: Red Skull
Red Skull was one of Captain America's first major villains and out of everyone on this list, he's probably the least likely to ever be redeemed. He has harmed many innocent people and not only that, but he is also a nazi.
His alliances with the Nazis run way too deep to ever consider Red Skull a redeemable villain. He fights for all things evil in the world and even if he attempted to change, his history with racism is too strong for it to ever be valid or acceptable.
Redeemable: Mysterio
Mysterio is more self-absorbed and jealous than he is villainous. He put people in danger simply so he could pretend to save them and be deemed a hero himself.
His idea to manipulate the world into thinking he's incredibly powerful and heroic was more insane than evil. Considering all he wanted was to become the next Iron Man rather than to take over the world or hurt people, it's likely Mysterio could be redeemed and may eventually turn into a real hero.
Too Evil: Ronan
Ronan the Accuser is known for many of his villainous acts. He harmed many refugees and most notably was responsible for the death of Drax's family. In the Guardians of the Galaxy, he heartlessly tells Drax about how his wife and kids screamed as he took their lives.
As one of Thano's minions, Ronan was so evil that he wasn't even loyal to his master. Once he discovered the stone's power, he wanted it all for himself, which later resulted in his own demise.
Redeemable: Loki
Loki may be the God of Mischief, but he's been shown to not be as evil as many expected him to be. There have been many times where he was shown to actually help save lives rather than take them, like in the movie Thor: Ragnarok. In Marvel's Avengers, he wanted to take over the planet earth, but unlike many other villains, he simply wanted to rule instead of destroying the planet.
Loki's inclination to save lives from being taken in Thor: Ragnarok, sparing his father's life, and the strong emotions of pain he displayed when his mother was killed show that he's not the evilest villain in Marvel.
Too Evil: Apocalypse
Being the first mutant ever born, Apocalypse held a lot of power in the Marvel Universe. He would bring destruction to every place he ever went to, with only one goal in mind: to cause the world's apocalypse.
His name is quite literal, as that is actually what he intended to cause. Considering all he wants is to destroy the planet, and with very little reason and care for the life on it, we'd say Apocalypse is far from being redeemed.
Redeemable: Hela
Hela wanted to rule Asgard, enslave its people, and have everything revolve around herself. Even though it sounds intense, it's not so far off from what her brother Loki attempted to do with Earth, and he's also proven himself to be quite redeemable over time. She's certainly shown to share the same sense of humor and dramatic flair.
In addition to that, no one can deny that Hela is actually entitled to the Asgardian throne by birthright. She was doomed to the underworld, despite being the eldest sibling. Her attempt to be Asgard's queen was actually valid.
Too Evil: Green Goblin
There is one thing that the Green Goblin can never come back from, and that's the death of Gwen Stacy. He's responsible for consistently trying to ruin Peter Parker's life and harm the people closest to him in basically every adaptation.
From threatening the lives of kids on a school bus in the first Spider-Man movies, to actually taking the life of Spider-Man's girlfriend, the Green Goblin is one villain that has gone too far so many times that we just can't see a redemption arc for him any time soon.