"I don't know why Superman is an example of how horror cannot find its way into his comic."

Not saying impossible, I'm saying it's more difficult. An example was given of Superman being placed far from a yellow sun, with diminished powers, fighting Aliens.  Yes, but he had to be depowered to be threatened.

Street level heroes can easily experience horror while at the top of their game. You can dump Batman into just about any horror scenario and make it work, somehow. Superman needs to be seriously depowered to get there, or there needs to be a good, plausible gimmick as to why he's under threat even with his powers. So that's an added level of clever that not all writers are up to.

The Silver Banshee (first appearance in JB's Action run) is an example of Horror that worked, but also an example of how Superman is less vulnerable. Silver Banshee's mystic scream "killed" Superman, but he was so powerful that the scream only stopped his heart and put him in suspended animation.

Captain America vs. Baron Blood really stand out in my mind as an example of Horror that works very well well with Superheroes. I agree that the street level heroes like Captain America and Daredevil or Batman and Robin would probably work better than the heavy hitters. Although Spider Man did have his own encounters with Morbius. All classics now. 

I do remember one funny instance when a vampire tried to tackle Luke Cage and could not penetrate his skin with a bite. He started to look for other sources, such as the eyes for example. Luke Cage was hypnotised and standing there as the vampire examined him for a weak spots.

I've often thought that Marvel should do a limited edition series where a few street level characters, such as Captain America, Daredevil and Nightcrawler for example were brought together under extraordinary circumstance and modelled briefly as vampire hunters. Each character would have some kind of "faith" that is being challenged in the story as they combat the Vampire Hoards.

The thing with a horror story is that there has to really be the chance of death to the hero and you have to get some macabre sense of dread or horror from the work. If the hero is too powerful and there is no real chance of them dying then there is no horror, although other people close to them could potentially be victems I guess. But I don't think that would be as compelling.

Edit: I will also note the Lovecraftian influence on at least the infamous insane asylum in the Batman story. Arkham is a well known town in Lovecraft's stories. 

An example was given of Superman being placed far from a yellow sun, with diminished powers, fighting Aliens.  Yes, but he had to be depowered to be threatened.

Again, as with every major corporate-owned character, I don't know why Superman himself needs to be threatened physically. Isn't psychological horror as effective on Superman as any thinking human?

Ed, I disagree with your assessment of horror. When speaking of serial fiction, using a central character who comes into contact with all manner of danger scenarios, any appearance of a supernatural event links the "chapter" of the serial to the horror genre. In most cases, a serial character will meet the horror elements in whatever modus operendi the character has, but in almost every case the story is horror, whether the character is in mortal fear or not.

If played straight, a vampire for instance instantly creates a horror story. You can say the BLADE movies are just action movies with vampires, but they're still horror movies. And the horror stems not from the hero's mortal danger, as the hero is invincible in these cases, but from mortal danger to other characters the audience come to care about. In the BLADE flicks, that would be Whistler, specifically, and whoever else is teamed up with Blade and garners audience empathy.

INDIANA JONES AND THE TEMPLE OF DOOM is not a horror movie, per se, but pulp adventures of the sort were often rife with horror elements. As long as some character is threatened by those elements, and most particularly the supernatural, I think the story in question has established horror credentials.

The thing is, horror doesn't work as well with most serial characters, outside of street-level heroes. Even then, you know Batman or Dr. Strange isn't going to become a victim, which is the core psychological element in all horror stories. Or, to put it another way, the victim is dead, which would be the "end" of the horror story. No, any character who experiences or is in conflict with a threatening, mysterious "unknown" is in a horror story.

Apparently the new Wonder Woman comic is putting this superhero/horror fusion to the test. I haven't read it yet, though I wish to, but I'm interested in the execution of such a bold move. Considering Wonder Woman's mythical genetics, she's not an illogical choice, if the writer is getting to the heart of horror, which is fear of the unknown.