Superman isn't just called the Man of Steel for nothing. He's invincibility to almost everything makes him a perfect candidate for the title. His powers to essentially defeat any enemy in front of him makes his list of weaknesses rather short. Sure, there are some obstacles that he can only conquer with the help of the Justice League. But even the league has admitted that without Superman, some situations would be unbeatable. But true fans remember that Superman always had two main weaknesses: Kryptonite, and Magic.
Now, there are a lot of magic users in the DC universe. Some are more powerful than others for various reasons since magic has different categories. Swamp Thing, for example, is considered a very powerful magic user, but he primarily uses the power of the Green, which is connected to the elemental force of all botanical life in the universe. So not all magic users are created equal. But there are few individuals specifically, who could kick Superman's butt any time.
10 John Constantine
The Hellblazer himself, it's been proven that John Constantine doesn't like a lot of people in the DC universe, and many don't like John back. He's an expert caster, conjurer, and sorcerer, who famously dammed a girl to hell as a young lad, when he summoned the demon Nergal under a different name, causing him to lose control of it.
Later on, he refines his skill, which he luckily uses for good. But if push came to shove, he's more than enough to give Superman a good spanking, which would probably be literal with him.
9 Zatanna
A magician and expert sorceress, Zatanna Zatara (try saying that many times) has been an ally to Batman and Superman for years. Jason Blood has stated that Zatanna is stronger and more skilled than him, and he often works alongside John Constantine in the Justice League Dark team.
Her powers are genetic and the only way she's ever been subdued while conscious is by gagging her voice, as she can expertly recite spells with words that don't even have meaning. She's even resurrected the entire city of Metropolis from ruin, so she's got more than enough power to defeat a man of steel, that's still a man.
8 Felix Faust
A classic Justice League of America villain and a mighty sorcerer who's thousands of years old, Felix Faust is no joke. He can control reality with his magical power, who surrounded himself with magical books as a way to further his knowledge on the subject.
He's been a worthy opponent of both Constantine and Zatanna, who are already high caliber sorcerers on their own. If he were to face off against Superman, who is weak to magic, it wouldn't take him too long to subdue or even kill the Kryptonian.
7 The Enchantress
A pre-crisis anti-hero turned Supergirl villain, June Moone and her alter-ego, The Enchantress - more famously known today as an original member of the Suicide Squad in both the comics and film - is a dangerously powerful sorceress who can alter reality and magical energy itself.
Her magic is more controlled when she is anchored to June Moone, but only by the limitations of what she can think to do with it. When she was unbound from Moone, she was a great danger to both the Justice League and the Justice League Dark. So she could easily defeat superman without putting an effort into the act.
6 Black Adam/Shazam (Captain Marvel)
The chosen champions picked by the Wizard Shazam, Black Adam and Captain Marvel share the same spot because they both have similar powers, but also because they both have proven to be a challenge for Superman in the past. The magic lighting both these characters can summon has proven to be detrimental to Superman in battle on multiple occasions.
Not to mention, magic strength seems to be a great counter weapon to sun-powered Kryptonian strength, seeing as how superman has found himself struggling physically against the powers of the wizard Shazam.
5 Etrigan The Demon
Son of the demon Belial and half-brother of Merlin, the rhyming Etrigan is one of DC's very first horror characters. He was famously bonded to the former knight of Camelot, Jason Blood, who gained immortality after he and the demon became one. Blood himself is an expert demonologist, but Etirgan's demon powers make him invulnerable to a great deal of injury, and his demonic nature allows him to enjoy pain as if it were a pleasure.
He can also breathe hellfire and has a degree of pyrokinesis. His strength has been stated to be more than a match for the likes of Superman, whose body is highly vulnerable to demonic fire.
4 Klarion The Witch Boy
A literal witch from a dimension of witches to whom magic came naturally, Klarions only issue is that he is a teenager, which causes him to not be taken seriously and be mandated by adults.
He came to blows with Etrigan quite often, who tried to send him back to his own dimension but proved a difficult challenge time and time again. His exceptional nature to dark magic allows him to conquer most challenges, so defeating Superman shouldn't be a problem for a witch like him.
3 Dr. Fate
Considered one of the most powerful spellcasters in the DC universe, his magic always appears in the form of the Egyptian symbol ankh. The powers Fae stem from his helmet and cloak, which belong to the wizard Nabu. His only true weakness is that the helmet requires a host in order to become Dr. Fate and that he cannot create counterspells for the magic cast against him.
Fate is one of the few individuals who can cast magic for dimension and time travel. Most of the DC universe agree, including Superman, he is not someone to trifle with.
2 The Spectre
A little force of nature, Jim Corrigan is imbued with the powers of God by The Voice, turning him into The Spectre: a spirit who exacts justice, and occasionally vengeance, on those who deserve it.
The power of the Spectre is almost unmatched in the DC universe, as his only weakness is needing a human host, and high-tier magic, which very few individuals can use. He's previously stopped Superman from doing certain acts which he felt intervened with the plans laid out, and he's stated he has no issue taking him out of the equation.
1 Trigon
The father of Raven and a powerful demon lord from an alternate dimension, Trigon is considered one of the most powerful beings in the entire DC universe. His powers rival only that of the Spectre, as he can not only warp reality, but also time, space, emotions, and minds. He's been set on conquering earth ever since Raven was born, and has gone to great lengths to achieve it, but failed.
He's a highly dangerous adversary of both the Teen Titans and the Justice League, meaning he is someone Superman cannot defeat on his own. But in recent animated films, he's easily defeated and even overpowered the Man of Steel, proving once and for all just how outmatched Superman really is.