There might be a young hero or heroine who opposes the Demon King. This character often has some unique abilities or a strong sense of justice that drives them to stand up against the Demon King's tyranny.
I don't know as I haven't read it. It could be a young adventurer, a wise old wizard, or a brave knight.
The story might involve the adventures and challenges of a powerful demon king in the diverse and complex world of the seven realms.
Well, one interesting plot could be the Demon King's first encounter with a powerful wizard from one of the realms. It's a clash of great powers and full of suspense.
Without reading the 'the demon king arrives novel', it's difficult to name all the main characters. However, based on the title, the demon king is central. There may be a prophet - like figure who foresaw the demon king's arrival and is trying to gather forces to stop him. And perhaps there are characters from the demon king's own realm who either follow him or betray him during his arrival in the new world.
The main character is surely the selfish demon king. There may also be some characters who oppose him, like brave knights or powerful mages.
There is likely to be the demon king - to - - be as the main character. And probably some supporting characters like his mentors, rivals, or friends.
Since it's a 'demon king retry novel', the demon king is bound to be a central figure. There could also be characters who oppose the demon king, such as brave knights or powerful mages. And perhaps there are some neutral characters who get caught in the middle of the conflict between the demon king and his opponents. For example, ordinary villagers or merchants who are affected by the demon king's actions and the battles that ensue during his retry.
In this type of novel, the most obvious main character is the selfish demon king. His personality and actions shape the story. However, there may also be other important characters. There could be a group of rebels, perhaps led by a charismatic leader, who are determined to overthrow the demon king. There might also be a love interest for one of the main characters, whether it's for the demon king (in a more complex and perhaps dark way) or for one of the good guys. And don't forget about the advisers or council members in the demon king's court. Some of them may play a role in either enabling his selfish behavior or trying to change his ways.
I'm not sure specifically without reading it, but there's likely to be the demon king - to - - be as a main character, and perhaps some mentors or rivals.
The main character is usually the demon king or a potential demon king. There may also be teachers or other powerful demons at the academy.