A comic hero is only as good as a villain. A villain needs to challenge the hero or add some depth to the character. So, a good guy that starts with less than honorable beginnings? Perfection. So to speak. They're frequently troubled characters that start out following someone else because they don't know any better. Then they make the hardest choice of their life.
Sometimes the person fighting for the little guy is a former assassin. Once in a while, they're a spy stealing state secrets for their home country. Other times, they're mercenaries simply following the money. However they got their start, these characters eventually made the choice to end up on the right side of the law. They've all gone on to make a larger impact fighting the good fight than not.
Comic heroes that started as villains
In this day and age, it's hard for a lot of people to imagine Deadpool as anyone other than Ryan Reynolds. The way he portrays the Merc with a Mouth is ideal for a lot of fans. And while he might not be the best role model, he's definitely not a bad guy. An anti-hero, really. Wade Wilson was much different when he made his first appearance on the panel-littered page.
He was very much a mercenary and didn't have nearly as much of a sense of humor as he is known for today. He repeatedly went against the X-Force and the New Mutants. He still had some mild sarcasm, but nowhere near the looniness he is known for today. He was modeled after DC's Deathstroke, after all.
Selina Kyle, Batman's on-again-and-off-again girlfriend, wasn't always the morally gray figure she is today. She started out as a hardline villain. She was a thief with no morals. She would steal from anyone. After the Crisis on Infinite Earths event, however, she's lived in more of a gray area.
This worked out for Batman since he kind of has a thing for her. She's given him a hand on more than one occasion, but Selina is still able to keep her ear to the ground. She's very much plugged into Gotham's underbelly. Again, this benefits Batman.
Pietro Maximoff is the speedster son of Magneto but not anymore. Nobody can keep up with these retcons. Quicksilver began his career in Marvel comics as a villain. Makes sense since his father was Magneto, the most notable villain for the X-Men. He and his sister, Wanda, fought alongside Magneto in the Brotherhood of Evil Mutants.
Eventually, he and his sister would join the Avengers only to leave and become villains again. It was a short stint where Pietro used his sister to try to take over the world, but he eventually came around and has been a hero ever since.
Jason Todd was the second Robin after Dick Grayson grew tired of being Batman's lackey. Todd was eventually killed at the hands of the Joker. When he returned to the land of the living, he had a lot of anger and resentment for Batman. He felt let down. He channeled that anger against Bruce Wayne and repeatedly tried to kill him.
Eventually, something was able to get through to Jason and he decided to become an ally of the Bat-family. He's now like the edgy brother amongst the Robins Dick Grayson and Tim Drake. Jason, under the guise of Red Hood, fights crime using guns. This goes against Bruce's philosophy, but it's better than having Jason against him.
We don't get to choose where we come from, only where we go. Natasha Romanov lives by that philosophy. She was once a Russian spy who worked for the Red Room. The Red Room was a training facility in Russia designed to produce the best of the best spies. Black Widow is partially responsible for Clint Barton beginning his career as a bad guy.
It's hard to look at Venom and not think he's a bad guy. Dark costume, sharp teeth, and sinister looking eyes, he has all the makings of a villain. It's even more difficult to not remember him beginning as a foil for Spider-Man.
Eddie Brock has come a long way from his spider-hunting days. He is currently fighting off the likes of Knull, the creator of the Symbiote race, alongside the Avengers and Fantastic Four. During the King in Black event, Brock lifted Mjolnir and became Captain Universe.
This power-absorbing mutant wasn't always on the right side of the law. She started out being led astray by her stepmom, Mystique. Rogue fought against her eventual X-Men teammates as an anti-human terrorist. She was a dangerous force to reckon with. The ability to sap a mutant's power and lifeforce is a deadly power no matter what. Couple it with a lack of empathy and it's inhumane.
Her life would eventually change once she was able to see the harm she caused. She approached Professor Xavier, the telepathic leader of the X-Men, and begged for help. He, of course, took her in and helped her turn her life around.
It might be difficult to see Plastic man as anything other than a hero, with the goofy personality and somewhat silly shapeshifting powers. He wasn't always this way, though. Patrick O'Brian began his days as a low-level thief (don't they all).
Eventually, when he gained his powers, he decided to turn over a new leaf. Being a former criminal helped him for a short time because he had connections in the underworld. He was able to use those connections to catch real criminals. Now he's a high-level member of DC superheroes.
Gambit, or Remy LeBeau, was kidnapped as a baby and raised by a clan of thieves. He grew up to be a confident con-man. A thief by trade, Remy would eventually change his ways and fight alongside the X-Men to protect the mutantkind. There was his time as Apocalypse's horseman, Death. Then there's his stint as a Marauder. Other than that, he's a total model citizen.
Gambit would go on to become the primary love interest for his teammate Rogue. Unable to have a physical relationship with her played a part in his move to become one of Apocalypse's horsemen.
It might be hard for a lot of newer fans to believe that the heart of the Avengers started out his superhero career as a villain. That's right, this top-notch marksman introduced himself to the Avengers by stealing from them.
His arc in the first Avengers movie was a nod to this origin. Loki manipulated him and pitted him against The Avengers. He then took part in a heist. So, his cinematic origins aren't too dissimilar from his comic book counterpart.