The most frightening aspect of a character.

To me, the most frightening is the kind of villain who truly, viscerally delights in causing pain to people. Because those kind of people are almost always beyond reason. To be in the power of someone like that... I can't imagine something worse.

 

I tried to think of fictional characters that could scare me ... and I think the aspects that I find most scary, are of those who are unpredictable and cruel. It borders a little to the unpredictability of terrorism, but I think there are many other ways it can play out. It dosen't have to do with the scale of power in an evil character, I mean, from the perspective of a given MC, a bullying streetbrat with a flair for cruelty can be just as terrifying as any dark lord. I have a few examples:

Joffrey, from "A Game of Thrones". You do mostly hate this little dolt and want to twist his neck around, but especially from the viewpoint of Sansa, he becomes really terrifying. Here is a spoiled and twisted child who has way too much power, and given his immaturity and growing paranoid insanity, he becomes increasingly more unpredictable and cruel.

Capa Barsavi, from "Lies of Locke Lamora". This guy is basically a medieval/rennaissance mobster/mafia boss. He is terrifying. He murders and punishes people in terrible ways. He can clap your back one second, and put a knife through it in the next. He keeps a strict order in his gangs. But what really accentuate his terrifying person, is actually his good relationship to Locke. He basically treats Locke like his soon-to-be son in law, which is absolutely horrifying, because you are constantly showed the consequences of betraying his trust, and that his friendship is a fickle thing.

Roose Bolton, "A Game of Thrones". Now if anyone has played the Telltale games version of Game of Thrones, you know what I'm talking about. This guy... ugh, he is so twisted. In the book he is also fat and ugly, but in the series, and the games, they made him younger, which, to me, makes him more terrifying. He is relatively young and handsome, and jovial (in his own, murderous way), but damn, he is rotten inside. In the game, you have to constantly maneuver with him as the Forrester House (basically a smaller version of House Stark), and he constantly puts you in impossible dilemmas, just to show his dominance.

So summing up, I actually think it also depends a lot on the POV whether the portrayed character is creepy or not. If the POV is scared of him, convincingly, with good reason, and have some sort of relationship with that creepy character, we will be scared of him or her as readers.

 

Fanatical leaders can be terrifying and loathsome at the same time.

People who are absolutely convinced that they have the solution to make the world a paradise, utopia, etc., and even with all the evidence in the world thrown in their face will never denounce their grand vision, no matter what horrific fate it may lead them to.

Throw in a ton of charisma, a talent for manipulation, a voice that hypnotizes, and lots of bad stuff can happen.

And to think that what might be even more frightening is the people willing to do anything so that this dream is realized, even if it is impossible.

The citizens in 1984 are a great example of this.

 

I think the scariest type of dictator is an ideology rather than a person. That's why, I think, people latch on to Big Brother as the villain of 1984 rather than O'Brien. People can be killed pretty easily. They can also make mistakes and care about others.
People can also be reasoned with. And if they can't, they're probably too insane or too stupid to really be held accountable for their own actions.
Ideas and images can't be hurt, make mistakes, care about others or really be talked to. They just exist and influence people.

In short: concepts or circumstances make for scarier villains.

I very rarely, if ever, like human villains who are unquestionably and irredeemably evil. Those always strike me as among the weaker types of villains. And when a human villain doesn't act like a human (with morals and depth), I generally have trouble taking them very seriously. They became more like cartoon characters.
I take to more seriously when a good person does something awful. The idea of good people doing bad is scary to me.

 

For me the scariest thing is betrayal. When you find out the villain was someone who you trusted and you thought you knew. How do you even trust your judgement or yourself after that? It's a terrifying thought and it can make you your own enemy when you start to doubt yourself.

 

Similar to WooHooMan, I think that one non-human thing above all is scariest: Some sort of fatal biological contagion. Put it in the hands of a shadowy, difficult to find/corner sociopath or psychopath, and especially one randomly targeting the MC's friends, allies, sympathetic background characters (like the young, loving families, etc.), and have no cure for it, and that's pretty terrifying.

The carrier could actually be a type of monster, deranged beast, swarm of tiny not-quite-natural creatures.

For human villains to be scary: If they themselves aren't shadowy & elusive for both MC and reader, then they need to be extremely intelligent, able to control events on a broad scale. Something like Light Yagami/Kira from the anime Death Note or any number of villains with far-reaching influence over the political, economic, and social fabric of a society.

 

I've always found loss of control to be the scariest thing I can think of. Thus the worst villain, from my point of view, would be one who uses mind control or other forms of control over other people. And then there's the whole trope of aliens that infect you and slowly take you over...eesh. Or the magic that turns you into a mindless slave...eesh again. Or hypnotism. Guaranteed to make my skin crawl.

 

I forgot to mention shape shifters.

Shape shifters terrify me.

 

Governments and corporations. They have the people and the power to stop at nothing to achieve their goals, and no matter how nefarious, they're so deeply embedded within the population and culture that almost every citizen believes their lies of "it's for the best", and the few who don't are powerless to change anything. The hardest enemy to fight is the one that's all around you but that everyone refuses to see; at least most people start to believe in ghosts and demons after enough evidence, but god forbid you not trust other humans. Contagions are pretty up there too. Not so much because they're fast and invisible, an illness can be survived, but because pandemics are a great way for corrupt governments and corporations to capitalize on the public's fear for financial gain or shits and giggles.

 

On the one hand, there are clowns... it's the fake smile that makes them scary, I guess, LOL. John Wayne Gacy would epitomize that.

Ideologues in general are a solid bet. Fighting an idea that can destroy not just you, but your way of life for everyone around you? The existential threat, not just personal. However, no character I can think of actually "terrifies" me when I read them. Disturb me? Sure. Perhaps I'm just too jaded after all these years, LOL.

Trickier question for me than it seemed.

 

Gah. Clowns. I have always hated clowns. And puppets.

I think it's my sensitivity to the Uncanny Valley effect that's to blame; I'm visually oriented and have an...affinity, maybe? to the human face. I just have this knack for noting and remembering the details of every human face I come into contact with, and whenever I'm confronted with something human-yet-not, it freaks me out so much. It just...is wrong. At the most fundamental level. And I react viscerally to that wrongness.

Call it overreaction, but I like to think it's just a strong survival instinct! XD

 

See, I think once you put the unstoppable, inhuman thing in the hands of a person, it looses a lot of its menace. The unstoppable, inhuman thing is scarier when no can control it.

I've never found clowns scary, honestly.
In fact, I seriously think clowns are meme-scary. It's as if people for so long went around saying "clowns are scary" that now everyone just accepts that clowns are scary. Like, clown scariness has worked its way into our collective unconsciousness.

Which, I guess if you're looking for a scary villain, one that all of humanity has unconsciously agreed is scary would be the way to go.

I'm going to second this. In fact, I think this is the best answer in the thread.
Nothing disturbs me more than mind control.
Likewise, no disease scares me more than Alzheimer's.
Anything that completely changes/destroys who a person is on a fundamental level against their will is really terrifying.

 

Well before even Poltergeist the movie put evil clowns on the movie map, as a kid I went to a haunted house, and the only thing tht scared me there was the damned clowns in the parking lot, LOL.

I no longer think they are scary, but I know many kids of my generation that at least felt uneasy around clowns. I would not be surprised if this didn't have some psychological connection to John Wayne Gacy, who was Pogo the Clown and a noted serial killer of boys in the 70's. Now rodeo clowns, I was always cool with them, LOL.

In the Space To Care study aimed at improving hospital design for children, researchers from the University of Sheffield polled 250 children regarding their opinions on décor for a forthcoming hospital redesign; all 250 children, whose ages ranged between four and sixteen, reported that they disliked clowns as part of hospital décor.[14] Many of them, including some older children, stated in the poll that they, in fact, actively feared clowns.[15][16] In other studies playing with therapeutic clowns reduced anxiety in children and improved healing in children with respiratory illness.

So, to each their own I guess, heh heh.

 

The scariest character/person to me is the one who can perform evil actions while completely convinced of their "goodness". I think of characters like Nurse Ratchet in One Flew Over the Cuckoos Nest - one who can mess with someone else's mind, even hurt them physically, and yet smile and coo as if being gently supportive, is absolutely creepy.

 

I generally don't find humans ( and other humanoids) scary.

What i find very scary are viruses. The greyscale from asoiaf. Especially if the last two books revealed that it have some form of sentience. Computer viruses and zombie viruses too.

 

For all intents and purposes, the biological effect is uncontrollable when you have a shadowy, evasive psychopath or sociopath going about and (seemingly) randomly targeting individuals. From the POV of the MC, the unseen adversary is little different than some abstract called "Nature" or "Chance" causing these things to happen.

Because I generally focus on the fantasy genre, when I think of these biological effects, I think of the villain whose mere touch can start a process of corruption and decay. Boils, dying flesh, and so forth—not necessarily a self-sustaining epidemic.

But they do not just exist sans people. Indeed, the scariest idea or concept you can imagine would be absolutely, 100%, without exception impotent if people weren't going about enacting that idea or having their actions informed by it. And I think it's easier on a person-by-person basis to confront and combat an idea than it is to counter some biological corruption, especially in a world with limited or no advanced medicine.