Projecting negative thoughts into his/her enemies heads-would be the answer to the title of this post. Think of the possibilities...you could bring down Anyone by messing with their heads. We are the sum of our thoughts after all. But it might not be visual enough, perhaps you were thinking more of jets of fire from their eyeballs, manipulating weather patterns or duplicating themselves thousands of times creating an army. The maximum amount of number of powers--mmm! Having too many super powers weakens the villain. In the sense that he would be impossible to defeat them, what makes a good story are flaws, if the villian is all powerful and can't be defeated what's the point?
In the TV show Heroes: Reborn (really good, by the way), there's a character that can not only read thoughts... But he can plant thoughts into other people's brain and make them do whatever he wants. Pretty terrifying to me. As for how many, it depends on how strong the ones he has are. If it's sissy shit, like making a flower grow, I imagine he can have many until it becomes too much. But if the powers are powerful, two maybe three at max.
A story doesn't need to have a villian that can be defeated though. Just look at lovecraft "villians". I myself think the most frightening power would be to deprive others of their own strengths listlessly, to be able to make someone forget or to make them go blind, to make them go numb or even paralyzed. This does however, like cazann34's idea, go under mental powers as well with similar implications. It would involve directly messing with the way certain parts of the brain work. A certain character of my own has this ability. As far as how many is too many, I really don't think there is a "too many" unless you don't know a way they can be defeated. It's really more dependent on how ridiculous their defeat is and knowing -why- they have such power. A villian that can absorb powers that's been around for a thousand years for example has more of an excuse, but that's not always the case and that alone already brings the question of "how does a hero who doesn't have even a tenth of the experience, knowledge or skills the big bad has defeat him". Special weapons and specific weaknesses are super cliche and just plain suck in my opinion, as well as suddenly gaining a power that stops the bad guy magically. These are things worth taking into consideration first.
I think what makes the most frightening villain tends to not be super powers at all. Think of it like this. Who do you see being more brave. Superman or Batman? Batman of course, right? I mean, being immune to bullets means there is no innate risk of being hit by them. So, there is no fear. No fear, equates to no bravery, since I see bravery as the act of facing ones fears. And yeah, I suppose any one who has been picked on can account to a strong bully being someone you are scared of. Yet, I don't think it is the peak. Bullies for all there ability to intimidate are not really effective. They tend to be one trick ponies. With one skill above the average. So to me, a villain that can talk himself out of a corner, who can account for missteps by having an escape plan, and who smart enough to create plans that can effect the world. That guy is scary as fuck. Because, the trick tends to be, you don't even know he exists until it is too late. Which means, you could have been working for him the entire time. Thinking your doing good and in reality doing bad. Course the above is only more awesome if you give him super powers. With the above concept. Powers you can't directly fight tend to be more scary. In the sense, you can fight a monster, even a bear can be brought down with a tool or trap. You can't directly fight poison. So poison tends to be slightly more scary. Though, mentally manipulating someone, as other posters have commented on, can be in the same ball park.
With mine, although mental, the situation I imagine would be more like this; imagine suddenly being paralyzed and having your vision blur out. You realize you've lost control and all feeling in your arms and legs before falling to the ground. You hear footsteps echoing louder in your head and you've forgotten about everything before. You can't remember why or how this is happening and you're forgetting even your name and it scares you, but not as much as the sudden absence of the sound of the footsteps, knowing something or someone is there, just watching you suffer, waiting, standing right in front of your vision-less, numb, vulnerable body. Suddenly you can't breath and your thoughts become like blurred reverberating noise in a panic, with the only form of sensory left being the sound of your heartbeat, your pulse and your internal organs. Everything tightens up inside and it feels as though the life is slowly being squeezed right out of your lungs, and just before you die, you forget everything; who you are, what your goal was, what the world even looked like. All you know is the feeling that there might have been something more to life, along with the feelings of suffering and terror. It takes advantage of some of our most deep rooted universal fears.
Well, that sort of plays into what I said. I used poison only as a reference to the concept. As I see two main forces here. 1. One you can fight directly, as in requiring physical ability to overcome something. 2. Something you can't fight directly. Something that more or less robs you of the ability to use your physical advantage. Whether this robbing effect comes from poison, mentally forgetting who you are or losing your senses doesn't much matter. Though, with the description you just used. I bet you would like one of my girls. lol. She has illusionary type powers and is a villain
Able to kill anyone in an instant, not having to touch them, maybe not even see them, just think about them. And in the most horrible way, boiling blood, flaying etc no one is safe, everyone who confronts the villain is dead
The ability to control their own author. Oh and an ability to hum some genuinely effective brown noise; that'd scare the bejesus outta me.
manipulation or the power to control others. The idea of not being in control of my own actions and being forced to do things i dont want to do is most frightening.
There are a few top notch frightening powers that come to mind: the ability to control time..being able to force their consciousness into another person pushing them out and killing the host.. Being able to change a person's soul/personality.. But I think that it's the non-supernatural powers that are the most scary. The personality traits that twisted and formed over years. Like the ability to kill without pause. Imagine a villian that didn't give you those few minutes, but got right to it and enjoyed the shock of their abruptness. Multiple personalities is another. Not knowing how to respond to the villian and being unpredictable is scary. I could go on, but yeah I think it's the things we can relate with that are the most frightening. And I agree with multiple other comments that as long as there's a weak spot, you can practically amp up the villain as much as you like.
For me, it's someone with enough clout to sway an entire nation to your way of thinking, someone with enough subtlety to commit horrific acts behind the curtains while keeping your population in a constant state of fear and “what if I'm next?” The super power is just an added spice of terror. I dunno about any of you, but this kind of villain scares the hell out of me more than a villain with overt usages of powers.
I think I know exactly who you're talking about, but I'm not gonna mention politics in this nice thread.
