One reason could be to create a sense of extreme tragedy or futility. By eliminating all the characters, the author might be trying to show that in the world of the novel, there is no hope and all are doomed. It could also be a very extreme form of making a statement about the futility of life or the overwhelming power of certain forces, like a cruel and inescapable fate or a devastating event such as a global catastrophe that no one can survive.
It would shock them. Readers usually expect some characters to survive, at least the main ones. So, when every character is killed off, it goes against their expectations and leaves them with a sense of disbelief.
One effect could be shock value. It can jolt the readers and make them more engaged as they try to figure out how the story will progress without that character. For example, in 'Game of Thrones', Ned Stark's early death completely changed the direction of the story and made readers more eager to see how the power struggle would unfold without his influence.
To set a dark or tragic tone. If an author wants to show that the world of the novel is a harsh place from the start, killing off a character early can be an effective way. For instance, in '1984', the way the Party eliminates people early on gives a sense of the totalitarian and dangerous world.
One pro is that it can create a huge shock value. It can jolt the readers and make them more engaged as they try to figure out how the story will progress without that character. A con could be that readers might get too attached to the character and become very disappointed or even stop reading. Another con is that it might disrupt the planned character arcs and plotlines that were centered around that character.
One ethical consideration is respecting the original creator's vision. If the character is important to the source material's overall narrative, killing them off might be seen as undermining the original work. Another aspect is the impact on the fan community. Some fans may have strong emotional attachments to the character, and killing them off could upset or disappoint those fans.
One reason could be to create a sense of shock or surprise. It makes the story more unpredictable. For example, in 'Game of Thrones', the sudden death of Ned Stark shocked readers and viewers alike, completely changing the direction of the story.
Fan Xian successfully assassinated the Qing Emperor and lived in seclusion in Jiangnan. He led a happy life with his wife, Lin Wan 'er, his concubine, Liu Sisi, his son, Fan Liang, and his daughter, Fan Shuning. The Qing Emperor had been killed by Fan Xian and Wu Zhu working together. The other people's endings included the Eldest Princess, Crown Prince, Second Prince, and others who committed suicide after failing to assassinate the Qing Emperor.
The ending of each character in the novel was as follows: Fan Xian successfully overthrew the Qing Emperor and supported the Third Prince to ascend the throne. He chose to live in seclusion in Jiangnan and lived a happy life with his wife, Lin Wan 'er. In the final battle, the Qing Emperor was heavily injured by Fan Xian and the others. In the end, he was killed by Wu Zhu's beam eyes. The Eldest Prince, the Second Prince, and Li Yunrui all committed suicide in different ways. Chen Pingping chose to confront the Qing Emperor and uncovered the Qing Emperor's plot. Lin Wan 'er gave birth to Fan Xian's second son, Fan Liang. She lived in seclusion with Fan Xian in Jiangnan and lived a happy life. The endings of the other characters were not mentioned.
The ending of each character in the novel is as follows:
Fan Xian successfully assassinated the Qing Emperor and chose to live in seclusion in Jiangnan, living a happy life with his wife, Lin Wan 'er.
Lin Wan 'er chose to live in seclusion in Jiangnan with Fan Xian and live a peaceful and happy life.
The Qing Emperor was defeated by Fan Xian and the others, and was eventually killed by Wu Zhu's ray eyes.
The Third Prince, with the help of Fan Xian and the others, successfully ascended the throne and became the new Emperor.
Chen Pingping: In order to investigate the truth behind Ye Qingmei's death, he confronted the Qing Emperor and was eventually ordered to die by the Qing Emperor.
[Fei Jie: Go to the Pacific Ocean with Ye Liuyun.]
The Shadow had always protected two generations of Headmasters and finally continued to follow Fan Xian as a Shadow.
Yan Xiaoyi was shot dead by Fan Xian in the battle.
Sigu Jian was injured in a battle with the Qing Emperor. Thirteenth Wang rescued him and brought him back to Dongyi. A few years later, he died after being stabbed by the Shadow in Dongyi.
Ye Liuyun was injured in the battle with Sigu Jian and left the Qing Kingdom with Fei Jie.
Ku He: In the battle with the Qing Emperor, he was hit by the Qing Emperor's zhenqi and died not long after returning to Northern Qi.
[Hong Sixiang: Killed by Ku He in battle.]
Wang Qinian followed Fan Xian to live in seclusion.
Yan Bingyun: Become the new Director of the Overwatch Council and continue to assist the new Emperor.