A possible plot could be that an alien parasite enters a human host. At first, the host is terrified and tries to fight it off. But as time passes, the parasite starts to understand the host's emotions and the host begins to realize that the parasite has its own consciousness. They gradually form a bond and fall in love. For example, they might start to protect each other from other threats, both from within the human world and from the alien parasite's original species.
I'm sorry, my answer didn't provide any information related to the fact that the male protagonist of the novel has an alien parasite called something mark in his body. The parasite in his body is of the highest level. Please provide more information so that I can better answer your questions.
The market for slither horror erotic stories is likely to be very limited. It would mostly consist of individuals with very specific tastes. Most readers tend to prefer either pure horror or pure erotica, and the combination of the two might seem off - putting to many. Additionally, from a publishing perspective, it would be a difficult genre to market and distribute widely without facing some form of backlash or censorship.
One movie that could potentially fit this theme is 'Life'. It involves an alien life form that has a rather complex and somewhat parasitic relationship with the human characters, though the 'love' aspect is more in the sense of the struggle and connection between the two species. Another could be 'Slither' which has a parasitic alien entity that takes over a small town. There are some underlying themes that could be related to a strange form of 'love' in the way the aliens interact with their hosts.
Once, in a dark forest, there was a creature with a slither belly. It moved silently among the trees. A hiker heard a strange slithering sound at night. As he shone his flashlight, he saw the glistening slither belly of a huge, unknown beast. He ran in terror, the sound of that slithering following him. He never returned to that forest again.
The unpredictability. You never know when or where the slither - bellied thing will appear. One moment it could be silent, and the next it's right behind you.
One common characteristic is their ability to attach or infect other organisms. They often rely on a host for survival or to spread. For example, they might attach to animals or humans like in many stories. Another characteristic is that they usually have some sort of adaptation to go unnoticed. This could be camouflage or the ability to hide within the body of the host. Also, they are often portrayed as having a negative impact on the host, whether it's causing illness, changing behavior, or draining the host's energy.
Some fanfictions also focus on the evolution of Slither Wing. They might explore different ways in which Slither Wing could evolve, or the consequences of its evolution, both in terms of its physical appearance and its relationship with other Pokemon and humans.
The concept of a slither horror story often involves elements of the unknown and fear related to slithering creatures like snakes or other reptiles. However, when the 'erotic' aspect is added, it becomes a rather complex and often controversial genre. In general, horror aims to evoke fear, and mixing it with erotic elements can create a unique, if not polarizing, experience. But it's important to note that this kind of combination might not be suitable for all audiences.