Out of all seasons of American Horror Story, Coven is arguably the best. Thanks to a perfect combination of dark humor, genuine thrills, and a collection of intelligent characters that remain some of the franchise's best creations, Coven became an instant fan favorite, one that's aging like fine wine.
The characters on the show were impressive, but not all of them were on the same intellectual level. In fact, some were actively reckless and thoughtless, putting their intelligence into question. Others were both cunning and ruthless, quickly demonstrating just how capable and brilliant they were.
Kyle Spencer
Out of all the characters in Coven, Kyle has the least to do. He starts as a popular fraternity student who dies in a tragic accident, only to return as a zombie-like figure brought back by the witches.
For most of the season, Kyle is nearly mute and struggles with even the simplest tasks. Because of his reanimated status, Kyle doesn't know how to function and becomes entirely dependent on Zoe, his love interest. He ends up becoming the coven's new butler, wasting the potential he had before his untimely death. Kyle is one of Evan Peters' least evil characters in American Horror Story, but he's far from the brightest.
Spalding
Similar to Kyle, Spalding has no real agency. He lives to serve the coven, especially Fiona Goode, to whom he's entirely devoted; he even cut off his own tongue to protect her secrets.
Spalding's only interest outside the coven is his extensive doll collection. Other than that, his life revolves around the Academy, even going as far as to describe himself as "the help," proving he has no ambition outside the walls of Miss Robicheaux's. Because he lives to serve, literally, he seldom acts on his own. Although he does gain some agency after dying, he remains passive, never coming up with plans of his own and settling for acting as a henchman.
Madame LaLaurie
The racist and murderous Madame LaLaurie is one of Kathy Bates' most unlikable characters in American Horror Story. She's a bigot desperately clinging to the past, trying to maintain a status quo that works only for her. Unwilling or outright incapable of understanding others, she's outright ignorant; what's worse, she revels in said ignorance, promising never to change.
Being from another time, LaLaurie is also a fish out of water in the modern world. Overall, LaLaurie demonstrates her lack of intelligence and critical thought in every action, gesture, and vile word that comes out of her mouth.
Misty Day
Misty Day is naive and trusting. However, she's also capable and fiercely independent, having lived by herself for a long time. Misty has some of the most impressive and unique magical abilities in American Horror Story lore and knows where and when to use them, showing her intuitiveness.
Furthermore, Misty is intelligent enough to know who to trust. She is also quite gifted at reading people, allowing her to thrive even in hostile environments. However, Misty often allows her emotions to cloud her judgment. For example, she's incapable of escaping her personal hell, becoming a literal victim of her own devices.
Madison Montgomery
Ruthless and Machiavellian, Madison is among the coven's most exceptional witches. She uses her talents only to protect her interests, which ironically ends up backfiring.
Madison proves herself a gifted and astute young witch. However, she usually focuses all her energy on getting her way. She is narrow-minded and often acts carelessly, endangering herself in the process. For example, she kills Misty without considering the unique abilities that already allowed her to revive herself once. She also refuses to revive Zoe, ensuring Kyle's animosity. Madison is so selfish that she doesn't consider the importance of allies, which eventually leads to her death.
Zoe Benson
None of the coven's witches is outright dumb. They are all capable young women, even if some are more inexperienced than others. Zoe is the most naive and unassuming of all the witches. She lacks experience in the "real world," and her naivete often leads to questionable choices.
Zoe suffers a dramatic shift throughout the season, becoming more assured and confident. However, she also makes many reckless choices, mainly bringing Kyle back from the dead, potentially endangering the entire coven. She also revives the Axeman, albeit unintentionally. Zoe never means to harm, but her instincts aren't as sharp as they could be.
Cordelia Foxx
Cordelia, Sarah Paulson's most iconic character in American Horror Story, is the kind and fair headmistress of Miss Robicheaux Academy. She is a capable witch committed to the coven, and the season's events strengthen her, turning her into the leader she was born to be.
Still, Cordelia commits some egregious mistakes during the season that show her lack of judgment. Her main sin is her marriage to Hank, a witch hunter who she allowed into the coven, endangering all her girls. Her desperate desire for a child also leads to some very questionable decisions, like approaching Marie Laveau in the first place. However, Cordelia is still a level-headed and sensible leader, a natural negotiator with an encyclopedic knowledge about botany. In other words, the only logical choice to be the next Supreme.
Myrtle Snow
Veteran American Horror Story actress Frances Conroy excelled as Myrtle Snow, one of the franchise's best creations. The eccentric but loving orange-headed witch is one of the wisest figures in the season, the Head of the Witches' Council, who always has a kind word for anyone who asks for it.
Myrtle is very knowledgeable and cultured. She recites poetry, knows about art and music, and has a deep interest in history. She is also cunning enough to hide her murder of the Council and mature enough to confess and accept the consequences of her actions. Myrtle is arguably the most mature and pragmatic of all the witches, although her loyalty to Cordelia does drive most of her actions.
Fiona Goode
As the Supreme, Fiona Goode is the most prominent figure in the coven. Youth-obsessed and ruthless, only her vast power matches her lust for it. She wishes to be Supreme forever and goes out of her way to achieve her goal.
Fiona proves herself a dangerous and formidable witch. She's always one step ahead of her enemies and comes up with plans that no one else can anticipate. She's also a master manipulator and demonstrates exceptional acumen in several instances. For example, Fiona finds a loophole in her deal with Papa Legba, proving that she's smart enough to trick a god. Fiona's sole defect is her overconfidence, which eventually brings her undoing.
Marie Laveau
It takes a really brilliant woman to remain Queen for centuries, safely hidden from the prying eyes of the outside world. Indeed, Marie Laveau was not only the most intelligent character in Coven but one of the most impressive in the entire series.
Marie knew when to show her power, displaying enough to command respect and allegiance from her subordinates while avoiding unwarranted attention. She knew the value of privacy and never allowed her pride to take over. Marie also understood the importance of alliances, even with her sworn enemies. As far as intelligence goes, no other character came close to Marie.