In the 'last man on earth Karl story', Karl is the central figure. He could be an ordinary person who was thrust into this extraordinary situation of being the last human. Maybe he has certain skills or qualities that help him survive, or perhaps he has to learn quickly how to endure in this new, lonely world.
Often, there is the theme of inspiration. Deku is very inspiring in the original story, and in fanfiction, he can inspire Shoto to be a better hero. Also, self - discovery. They both are on a journey to discover more about themselves, their powers, and their place in the hero world. In fanfiction, this journey can be elaborated on in different and interesting ways.
One common theme is redemption. Dabi, with his troubled past, often has a journey towards redemption, and Shoto can play a part in that. Another theme is family. Given their complex family relationships in the original story, fanfics often explore how they deal with family issues together.
No, it is not appropriate. Creating or distributing sexual fanfiction involving underage or fictional characters in a sexual context is unethical and often violates the terms of use of various platforms. Such content can also be considered a form of inappropriate objectification.
Well, 'shoto todoroki abused fanfiction' might be centered around the idea of taking the character Shoto Todoroki from the original source material and putting him in an abusive context. This could be physical, emotional, or psychological abuse. Some writers may use this as a means to develop the character further, to show his strength in overcoming such difficult situations, or it could be a way to delve into the darker sides of the fictional world in which he exists. It could also be a form of expressing the writer's own creativity and interpretation of the character's potential experiences.
Karl Benz's success lies in his invention of the first practical automobile. He had the vision and engineering skills to create a vehicle powered by an internal combustion engine. His Benz Patent - Motorwagen in 1885 was a revolutionary step. This allowed for individual transportation in a way that was previously not possible. His success also led to the growth of the automotive industry, as his ideas were further developed and improved upon by others over time.