I'm not entirely sure which 'Invicible' you specifically refer to. There could be a comic book series called 'Invincible' which is about a teenager named Mark Grayson who discovers he has superpowers as his father is the most powerful superhero on the planet. He has to navigate through a world full of other super - beings, facing challenges both in his personal life and in the greater superhero community.
Power struggles are a significant part of the story. There are various factions of super - beings vying for control or trying to maintain peace. This leads to intense battles and political intrigue within the superhero community. Also, the theme of betrayal, as Mark discovers things about his father and others that he never expected, adds depth to the full story.
Well, the theme of social invisibility is quite prominent. In the novel, the invisible man represents those who are overlooked or marginalized in society. It also touches on the theme of science and its consequences. The experiment that made him invisible had unforeseen and complex results.
The invisible man himself is of course a crucial character. He drives the whole story forward with his experiences and actions. There might also be the scientist who made him invisible, who is important as the originator of his condition.
The main distinction of porn with a story genre from regular porn is the presence of a coherent narrative. Regular porn often jumps straight to the sexual action, while the story genre tries to add some kind of story framework around it. But in the end, both are adult-oriented and feature explicit sexual content.
Well, it's hard to say for sure. The concept of 'porn-like' is quite subjective. Some might consider certain novels with excessive sexual descriptions as such, but it depends on individual perspectives and cultural standards.
In many places, 18+ porn comics are considered illegal. This is because they can have a negative impact on society and violate moral and legal standards.