Super Mario Villains Who Really Aren't Evil
He's painted evil by others who have heard of his seemingly terrible deeds. While he is a pirate captain who conquers others and hoards treasure, that's similar to other pirate characters and even people. As shown after his defeat, he does not display any real evil, as his only motive is to protect what is his. On top of that, after Mario returned his Skull Gem used to power his ship, Cortez attacked the invading X-Nauts and helped Mario to defeat them. Cortez becomes allied with Mario, making him the only villain in the entire Paper Mario franchise to completely reform.
Vivian is a reluctant villain, forced to do everything her sister Beldam does, and punished if she doesn't. Upon realizing who Mario is and that he's the only person who's ever been kind to her, Vivian finally finds the courage to break away from her self-absorbed sisters and join Mario on his adventure.
He doesn't antagonize Mario or his friends, or even commit any villainous acts. All he does is ask to duel with Mario in order to prove his strength, and when defeated, he graciously accepts his loss and gives Mario a super handy item.
All she did was make Stupendous Stew, which is Volbono's specialty dish. She wasn't even allied with Bowser; he stole her Stupendous Stew by himself. This poor bird didn't deserve to be fought.
His job was to protect the Binding Band, and his anger is due to Bowser stealing it for his wedding. He isn't evil.
The only potentially evil thing Booster has done was try to marry Peach, but he probably thought it was just a make-believe game. He likely wasn't serious about marrying Peach, as he wasn't bitter when she left to join Mario on his adventure. As such, you can't really hold that against him. As it turns out, Booster just enjoys playing with other people.
He's only an antagonist until you wrest the championship from him. If you think about it, he's just like those kinds of sport players that are hellbent on preserving their rank and reputation.
Kent C. Koopa is greedy for money, but so are other characters and even many people. At least he's respectful in combat and also gives Mario fair warning about what he's capable of. After being defeated, he backs off peacefully without further conflict.
He may be a pirate, but he has a code of honor. He's also courteous in battle and willing to admit his defeat. Jonathan Jones is only believed to be evil because of Yaridovich's deception.
Lemmy is another reluctant villain. I think it was said somewhere that Lemmy would rather perform in a circus than commit to the Koopa Troop's conquest.