Once Upon A Time is a fairytale show that, while technically following the arcs of the heroes, is all about the villains. They are the ones that are most interesting and the ones given detailed backgrounds explaining why they are the way they are. If ever there was a show to make villains sympathetic, this is it. Nearly every villain gets some kind of redemption arc, and almost all of them are motivated by love.
Most of the show's villains were relevant for one season and then never mentioned again, and few had lasting impacts on the rest of the characters. In addition, most of the villains, with Regina being the obvious example, changed enough throughout the show that they became heroes. When it's all boiled down, two villains had the biggest impacts on the show and the other characters, showing up often enough and acting cruelly enough to make them the best villain of the show: Cora Mills and Rumplestiltskin.
Cora Mills Was The Best Villain
Her Decisions Made Regina And Zelena Villains
While Cora Mills might not be thought of as a central villain, her daughters certainly are, and she was the one to make them who they are. Cora raised Regina under strict control, using magic as a punishment. When Regina found love, her mother took it away to force her into an unwanted marriage, and then consistently continued to meddle in her life even after being sent away, pushing Regina to be her worst self.
As for Zelena, Cora abandoned her in the forest to die, and then ignored her for the rest of her life. In addition, audiences later found out that Cora knew exactly where Zelena was, tracking her down to save Regina, only to abandon her yet again, making Zelena the jealous and insecure villain that audiences saw in season three.
She Was Motivated By Power, Not Love
Almost every villain in this show was motivated by love, which makes Cora stand out with her famous "Love is Weakness" slogan. Cora had the opportunity for love with Rumplestiltskin or with her husband Henry, who seemed to adore her. Instead, she ripped her own heart out so as not to be influenced by it again.
Cora Mills was all about power, doing everything she could to become royalty. It's no wonder that she became the Queen of Hearts when she wound up in Wonderland; it's been her path the entire show! While other characters are redeemable by their love-based motivations, she had no such explanation, which made Cora the best non-series regular character in the show.
She Darkened Snow White's Heart
Although audiences found out that Snow and Charming did some awful things in later seasons, Snow was generally seen as the paragon of good. Except when it came to Cora, where she manipulated Regina into killing her mother, creating a dark spot on her heart.
Cora tried to corrupt Snow from childhood, offering her a chance to save her mother by choosing someone else to die. While it didn't work then, something about Cora was dangerous and anger-inducing enough for Snow to do something terrible, which fundamentally changed her nature and perception of self.
She Killed Nearly All The Survivors Of The Dark Curse
One of the often-overlooked parts of Cora's time on Once Upon A Time took place in the Enchanted Forest. While audiences latch onto her killing Regina's true love and attempting to kill Rumplestiltskin, they frequently forget that she massacred an entire village of people.
Those in the Enchanted Forest who didn't get taken by the Dark Curse formed their community, which functioned relatively well until Cora didn't find them useful anymore. When the heroes return to the village, they find everything destroyed, with villagers sporting bloody chests from hearts ripped out.
She Owned More Hearts Than The Audience Even Knows
Cora Mills is the Queen of Hearts, in large part because she had a knack for taking hearts. However, while the audience sees a room full of beating hearts, it is rarely addressed just how many people Cora was controlling. With a room so large in the Enchanted Forest alone, there are easily hundreds of people under her complete control at any given point in time.
Regina's control over Graham in season one was looked at as vile and unforgivable, but audiences have to wonder just how many people Cora stole the agency from to get and keep the power she so desperately sought.
Rumplestiltskin Was The Best Villain
He Trained All The Mills Women
While Cora may have inspired Regina and Zelena to become villains, Rumpelstiltskin trained them and pushed them along darker paths to become villains capable of casting the Dark Curse.
In addition, he was the one to train Cora herself, meaning that who she became and what she did was in large part due to his influence. While she ended up hurting him, rather than the other way around, she would never have had the ability to do the many villainous things she did had he not saved her and trained her.
He Caused Trouble Every Season
Rumpelstiltskin was in all seven seasons and 137 out of 156 episodes, the highest of any true villain. While Rumple was often looked at as a redeemed villain like Regina, he had a villain 'twist' at least once a season.
Rumpelstiltskin was a powerful force to be reckoned with, and that meant that when he inevitably turned every season, he shifted the scales of who was winning every time. He only really fought with the heroes if it was for his good, which meant that the second it wasn't, he switched sides again, leaving everything in chaos.
He Guided Nearly Every Villain On The Show
If the writers needed an explanation for who a villain was, how they turned evil, or why they were relevant to the story, they almost always turned to some past whim of Rumplestiltskin. Spoilers ahead: Peter Pan was Rumpelstiltskin's father; Captain Hook was his nemesis; Zelena was his ex-pupil; the Queens of Darkness were brought together by his to get the Dark Curse; the Black fairy was his mother... the list goes on.
Because he had a connection to all of the other villains, there was almost always a scene where he met them and pushed them to be darker. Because of this, there is an argument to be made that he was responsible, at least in some part, for virtually every bad thing to happen in the Enchanted Forest and Storybrooke.
He Constantly Manipulated Belle
Rumplestiltskin's redemption arc frequently was connected to his relationship with Belle, who he originally forced to be a servant in his castle. There's more cause for Stockholm Syndrome here than in the original Beauty and the Beast, and it only gets worse from there, making audiences hate Rumplestiltskin at times.
Throughout the show, his temptation toward the darkness would overcome him, and he would have to lie to and/or manipulate Belle to get away with it. She could never seem to leave him for good, leaving many audience frustrated every time he fell back into his bad habits. While it was only one person he was hurting, Rumbelle's relationship was so beloved by fans that it felt personal every time he broke a promise.
He Was The Show's Final Villain
When all is said and done, Rumplestiltskin began the show as a villain and ended the show as the central villain—although ittedly, it was a variant of him that did so.
Wish Realm Rumplestiltskin was a version of the character who never found love, and he shows off just how good Robert Carlyle is at playing a demented evil character. The showrunners couldn't think of a better big bad than Rumplestiltskin, and it would be hard to argue that they ever wrote one, with Wish Realm Rumplestiltskin undoubtedly the best villain of season 7.