One cosplay horror story is about a girl who cosplayed as a popular horror movie character at a convention. A strange man started following her around, believing she was the real 'evil' character from the movie. He got too close and made her feel very uncomfortable.
One more common horror story is dealing with the accessories. Homestuck cosplays often have a lot of small and detailed accessories. A cosplayer could lose one of these important accessories right before or during the event. It might be a small charm or a unique piece that really completes the look. Without it, the cosplay just doesn't seem right and the cosplayer is left feeling disappointed and a bit self - conscious.
I heard of a case where a cosplayer bought a very elaborate cosplay outfit from eBay for an important convention. The seller promised fast shipping. However, the package got lost in transit. When the cosplayer tried to track it down, both eBay and the seller were not very helpful. So the cosplayer had to scramble to put together a new cosplay at the last minute.
A common one is misrepresentation. Sellers might use photos of really nice cosplay items but send out something completely different. For example, a beautifully designed sword prop in the picture could turn out to be a flimsy plastic thing in reality.
One horror story is when a cosplayer's expensive and carefully made costume got ruined by someone accidentally spilling a drink on it at the convention. The cosplayer had spent months on it, and it was a real heartbreak.
One of the 'Hetalia Horror Stories' could be about a character getting lost in a haunted version of their own country. They might encounter strange apparitions that resemble historical figures in a distorted way, which adds to the horror as they try to find their way out.
One horror story could be about overly possessive fans. There were cases where some fans would attack others who didn't share the same 'ship' (relationship pairing) in the Hetalia fandom. They would send mean messages and create a very hostile environment for those with different opinions.
One common element is the distortion of the hero's appearance. For example, a cosplayer might see a warped version of the hero they are cosplaying, which is really creepy. Another is the feeling of being followed or watched by something that looks like their cosplayed hero. It gives a sense of unease.
One horror story could be about a cosplayer who spent months making an elaborate Homestuck cosplay. At the convention, someone accidentally spilled a huge drink on it. All that hard work ruined in an instant. It was a nightmare for the cosplayer as they had put so much time, money and effort into it.
One horror story is when a cosplayer got an eye infection from cheap, unregulated cosplay contact lenses. The lenses were not properly sterilized, and soon after wearing them, their eyes became red, itchy and swollen. It took a long time and medical treatment to get better.