Despite being nothing more than exceptionally resourceful and determined human, Billy Butcher is arguably one of the most dangerous and strongest people with superhuman abilities and somehow coming out the winner.
It seems like a given that Billy is just the type of person who would be able to survive to the end of a horror movie, but while he would easily defeat some of horror's most iconic monsters and villains, there are some that would likely wind up defeating him too.
Could: Damien Thorn
Most people would be pretty intimidated by the antichrist, even if it was just a little kid. However, most people aren't Billy Butcher.
The fact that Damien Thorn is just a little boy wouldn't likely throw off Billy for an instant. It seems like Damien has some undue influence over the people around him, however if Billy knew that an evil child was running around causing havoc he would likely just walk up to him in the street and off him without a second thought.
Couldn't: The Overlook Hotel
The Overlook Hotel from the Stanley Kubrick classic The Shining as well as the intriguing Mike Flanagan sequel Doctor Sleep has proven to be a worthy adversary to even the strongest minds.
Billy is tough, but it doesn't take very much to push him towards violence, so a demonic hotel that can take possession of him and force him to do dastardly deeds wouldn't have much trouble getting what it wants out of him.
Could: Pazuzu
Pazuzu is a demon capable of possession, and it seems to be very adept at emotional and psychological manipulation. However, it would meet it's match with Billy Butcher.
The only emotion that Billy seems particularly comfortable tapping into is rage, and it seems likely that whatever manipulation moves that Pazuzu tried on Billy would only drive him to kill it even more quickly and violently.
Couldn't: Annie Wilkes
Annie Wilkes may just be a human, but if Billy ever found himself in Paul Sheldon's position he'd be in much bigger trouble than he would be if he was facing off against a more supernatural threat.
Annie is human, but she's extremely volatile and requires a delicate touch. Billy isn't exactly a good liar, nor is he particularly patient. He doesn't have it in him to persuade and manipulate her in the long term without his real feelings coming through.
Could: The Xenomorph
The Xenomorph is one of the most iconic and frightening creatures in film history, and it is an alien that is quite difficult to kill.
However, Billy is someone who is very creative when it comes to violence, and he is not afraid to go balls to the wall and risk his own life to defeat his enemy, which is exactly the disposition that defeating a Xenomorph requires.
Couldn't: Hannibal Lecter
It seems ironic that Billy would have an easier time fighting against mythical beasts and demons than he would against regular humans, but it's also pretty on brand for his character and goals.
Hannibal Lecter is a terrifying villain not because he's incredibly powerful, but that his skills with mental coercion and manipulation are expert enough that he convinced a man to feed his own face to dogs.
Could: The Thing
The fact that Billy only cares for the few people he truly knows well and couldn't give a damn about everyone else in the world is tragic in the broader sense, but would be incredibly convenient if he found himself in a situation going up against the Thing.
He would either be able to suss out a fake friend in under five minutes, or he would just kill someone he didn't know and not take the risk that they were a fake.
Couldn't: Freddy Krueger
It's strange that in the horror world full of monsters, one of the truly impossible to defeat killers of the world is Freddy Krueger. But when a serial killer becomes the master of the dream world, it really is pretty much impossible to escape him.
Billy would undoubtedly find some creative ways to avoid sleep, but that would only work for so long, and then he'd be a goner.
Could: Pennywise
Pennywise might be an ancient evil from another dimension, but it would appear that the only thing needed to defeat him is the belief that he can be defeated.
Many other characters would fall flat on this, but Billy's self belief when it comes to going up against creatures that are incalculably more powerful than himself is pretty high. If he believes he can destroy Homelander, he'd have no problem going up against Pennywise.
Couldn't: Paimon's Cult
Subtlety truly is not Billy's strong suit, and the manipulation of a shadowy group of lunatics like Paimon's cult would probably have his family ripped apart before he even knew what happened to him.
Billy is strong, but his lone weakness is the people that he loves, so he would have a tough time defeating any enemy that could hurt them.
