I'm not entirely sure specifically as there could be various translations of the 'Mo Dao Zu Shi' novel. Generally, it's a story full of complex characters, a unique fantasy world with elements of magic, mystery, and relationships. It likely involves the adventures and growth of the main characters in a world with different sects and powers.
Character development is a key characteristic of good 'Mo Dao Zu Shu' fanfiction. It could show how the characters grow and change over time, perhaps in response to new challenges or relationships. The dialogue should also be engaging, reflecting the personalities of the characters and adding to the overall flow of the story.
There are also fan - made 'mo dao zu shi novels' that can be quite interesting. These often take the existing characters and settings and create new adventures for them. They might explore different aspects of the characters' personalities or relationships that the original might not have delved into as deeply.