Fight to the Death!

I mean, just look at him.

The man is a beast and clearly jacked, his blood is literally steroids. He could probably shrug off just about any damage any killer could do to him although I do wanna say some runner ups:

Doctor. Electrocution is no joke and with the power the entity gave him the guy could electrify everybody at once, the guy is no slouch to melee combat either his arms literally ate his sleeves bro. They gone.

Surprise pick: The Clown. Don't let the belly mislead you he was an athlete who "grew tall and strong" so he is definitely physically capable, the afterpiece tonic I think might actually seal the deal for a lot of the killers. Being dazed, disoriented, coughing a whole bunch he'd throw off the aim of killers like the Deathslinger or Huntress, and he'd eventually wear down even super strong killers like the Oni. Ngl this big boi is pretty dangerous

Out of everyone here, The Oni is the only one who actually has combat training.

Lets list off why all of the other killers will be smashed into bits by The Oni:

The Spirit - While her power to phase walk is useful against Survivors, it's not particularly useful when versing other killers in the game. Not to mention her shattered Katana wouldn't be much of a pain for the other Killers to deal with. In fact I think they can just tank the hit.

The Wraith - His only strength is his Bell, which he can use to turn invisible. Aside from that, he can't really do much. He cannot hit or attack his enemies while invisible, he has to come out of cloak for that. And given that The Oni is aware of his enemy's presense at all times given his training and his perks such as Zanshin Presense... Yeah, he is dead.

The Hillbilly - He may have his chainsaw, but aside from that he isn't much of a threat. His chainsaw requires him to rev it up before he can go for the kill, which isn't going to be a problem for a Killer like the Oni who can just basically take it off his hands and break it with his own bare fists. Point once again, goes to the Oni.

The Nurse - Her ability to blink may as well just be used to run away. Her body feels more fragile than the other killers given the fact it takes her quite a bit before she is able to choke a Survivor to death. Not to mention her figure as well as the inability to run away and just float. I can see the Oni breaking her whole body.

The Hag - Hahahahahaha no. She's a cannibal who literally looks like she is a wooden stick you can just break with your bare hands. Oni wins this by a long shot. Her weapon is literally her hands, and I doubt that'll be enough to go against The Oni and his armoured up body.

The Huntress - She may be able to stand a chance against the Oni, mainly because she primarily goes for range whilst the Oni primarily goes for melee. But I doubt she will last long if he can muster enough Blood Orbs for Blood Fury, her 110% movement speed isn't doing her any favours either.

The Deathslinger - The Redeemer can barely injure survivors unless he stuns himself, he is so dead when facing the Oni.

The Plague - May be able to weaken the Yamaoka Demon. But not for long. Considering wherever she is, there will be pools of devotion nearby, I doubt he will be too bothered by her ability to puke in his face.

Freddy... he´s actually the only one who´s unstoppable. His Powers actually make him invulnurable while his victims are totally vulnurable to his powers

Where dod you come up with this ??? In the Movies he killed people that didn´t fear him because they weren´t even aware he existed... Can´t be afraid of something you don´t even know exists

Sorry but this makes no sense. Freddy would have never existed in the first place if your theory would be true, because nobody would be in fear of a man who is no longer alive.

I guess you misinterpreted something. Freddy killed many people who didn´t even have a clue that there ever was a serial killer with the name Freddy Krueger... accoording to what you´re saying they would have to be in fear of him, but how can they even fear him when they never knew anything about him even about his pure existance. The logic is missing.

Here's the thing, the question deliberately specified all "non-licensed characters"

So I have no idea why ya'll talking Freddy in the first place.

Given the amount of unknown variables associated with this theoretical death match, and the fact that all the participants are fictional characters, any answer is purely subjective.

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In other words: any of the Killers could theoretically win; depending on who writes out the encounter. It's the same as all those superhero 'verseus' things.

So because she's my main, I'll go for Huntress. Lengthy explanation below.

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She's canonically killed loads of people; whole villages and groups of soldiers with actual guns (not Deathslinger's lame harpoon) singlehandedly. Given her 'Me v. Everyone Else' combat experience; I think she has the best chance of surviving a death match.

Meanwhile, Oni was done in by an angry mob. Don't get me wrong, he definitely has a pretty good chance: he's killed a ton of highly dangerous things and dispatched multiple foes ganging up on him. But he's also had a lot of close calls: scars aren't victories, they're mistakes that could have gotten you killed - and he's covered with the things. He makes any slip ups against Spirit, Wraith, or Huntress, like he did against his dad, and they won't hesitate.

Plague has literally never killed anyone and as a handmaiden turned priestess presumably has little to no combat experience. Her sickness could spell soon for another Killer (if they have to get close to kill her), but it won't save her.

Spirit does know what she's doing with her katana, having beaten a gang of boys to death with a wooden practice sword, but she's a semi-nude, Survivor-tall stick: assuming she can die, she probably will if she gets hit by even a glancing blow.

Hillbilly suffers from all kind of physical impairments: sure he's got a chainsaw and has terrorized farmers and cattle; but he has no fighting experience. One on one against Trapper, Oni, Wraith, or Huntress in a hand-to-hand fight he's at a disadvantage (Huntress of course, also doesn't need to fight hand-to-hand).

The Deathslinger can harpoon one of the Killers if they're within 18 meters, but then he'll need to spend about 2 or 3 seconds reloading while he's just some skinny Hollow cowboy with a bayonet. He has been in his share of fights; but they're mostly gun fights were he had a gang to back him up; not melees alone against a mob.

Hag has magic rituals and a giant claw on her side, but she's also literally a zombie made of mud - assuming she can die, a good swift kick might kill her.

The Nurse can teleport, but once she arrives she's just a floating nurse with a bonesaw (for about second before succumbing to her fatigue) - assuming she can die, she has a very uphill battle against the other Killers.

Trapper has only really ever brutalized the unaware and non-combatants. He's cunning, big, and has a machete, but that's all he has going for him.

Everyone sleeping on the Wraith of course, ignoring the fact that his primary weapon is the spine and skull of a guy he RIPPED APART WITH HIS BARE HANDS LIKE HE'S THE FREAKIN' DOOMSLAYER! He doesn't need a bell; if twinkletoes here can get close to any of the other Killers they're mincemeat. So why not him as winner? Well, Huntress is a huntress (i.e. - her daily survival depends on tracking things that don't want to be found) with ranged weaponry that she wields with deadly accuracy. And did I mention she got bored of killing bears and wolves? Because she got bored of killing bears and wolves - and not with beartraps either, Trapper. Wraith's speed, stealth, and insane ferocity would give him an huge edge against probably every Killer in a 1v1 but her, and even with her it might theoretically be a close thing.

While Doctor has his big stick, his big muscles, and his electric hands: he's only really ever killed people that were literally defenseless - well his 'patients', and his fellow doctors at Léry's; but were a bunch of bored psychology doctors really that much of a threat for a deranged man with a giant d***o? I don't really think so. His madness ability could help him, but it takes time to charge. He has a chance, but he doesn't have a very good one IMO.

Clown is old, overweight, and uses a tiny knife. In his prime maybe he'd be threatening, but as is I think even Hag or Nurse could easily take him during one of his coughing fits. Barring a few miracles he's guaranteed to lose.

The Legion is actually really threatening in a death match thanks to their numbers. As Oni's lore makes a point to show: numbers can triumph over pure skill or strength. That said, I don't think there are enough of them to make too much of a difference against any of the heavier hitters: a single swing or two of Oni's katana or kanabo could kill or cripple multiple of them, Huntress' hatchets would kill or maim them into ineffectiveness, and Wraith could rip and tear them to pieces. If Legion could get the jump on the Killer in question, maybe, but I don't know.

Spirit is the only killer that cannot die, because they're already dead. All of the other killers (with the exception of Freddy) are physical, and can be killed.

If Spirit can be killed again, then probably Oni. The Yamaoka family is full of beasts.

If we're talking without the entity Caleb's gun can mess someone up, their guys would start coming out as soon as he starts pulling but with the entity oni would win