Well, obviously, the last man himself is the most notable character. His character would likely be complex, as he has to deal with the extreme situation of being alone. There might also be memories or hallucinations of other people that could be considered 'characters' in a sense, like his family or friends from before he was the last man.
If there are any non - human entities, they could also be important characters. For example, if there are intelligent animals or some kind of alien life forms that he interacts with. But often in 'the last man' scenarios, it's mainly about the internal struggle of the last human, so his own different mental states could be seen as different 'characters' within his mind.
Orson Scott Card is another important author in this genre. With 'Ender's Game', he created a unique and thought - provoking story. His ability to write about military strategy from the perspective of children and also explore deep moral and ethical questions within a science - fiction war setting makes his work stand out.
Lessa is also notable. She has a special connection with her dragon and is a key figure in the Pernese society. Her character is complex and she often challenges the norms and expectations of the society she lives in.
I'm not sure specifically as I haven't read it yet, but typically in science fiction, there are often scientists as characters. They might be the ones trying to understand and deal with the new and strange elements of these four futures.
Since I don't know the details of this 'the last castle science fiction', I can't say for sure who the main characters are. It could be a brave hero leading the defense of the castle, or a group of scientists who are using the castle for some important research in a sci - fi world.
One of the notable authors in 2020 science fiction was Cory Doctorow. His works often blend technological concepts with social commentary. For instance, his stories might explore how digital rights and privacy play out in a future society filled with advanced technology.
One of the notable authors in 2023 science fiction was Kim Stanley Robinson. His works often explore complex scientific concepts and their impact on society. Another was Ann Leckie, known for her unique take on space opera and post - human civilizations. N.K. Jemisin also made her mark with her thought - provoking stories that blend science fiction with elements of mythology and social commentary.
Some of the well-known science fiction authors include Arthur C. Clarke. His stories often explore futuristic concepts and technological advancements in a captivating way. Another is Ray Bradbury, known for his imaginative and thought-provoking tales.
Elric of Melniboné is one of the most famous. He is a complex anti - hero, a brooding albino with a cursed sword. Another is Jerry Cornelius, a kind of dandyish, time - traveling figure who gets involved in all sorts of wild adventures across different eras and realities.
One of the main themes could be survival. In such a story, the last man might be facing various challenges to stay alive, like finding food, shelter, and dealing with a desolate environment. Another theme could be loneliness. With no other humans around, the psychological impact of being alone would be a significant aspect.
There's Griffin, of course. He is a complex character who starts out with a thirst for knowledge and ends up a power - hungry and desperate man. And then there are the people he interacts with, like Dr. Kemp. Dr. Kemp becomes involved in Griffin's story when Griffin reveals his invisibility to him.