There is no fixed rule for naming characters in novels. Generally, the author of the novel names the characters according to the needs of the character's personality and storyline.
I prefer to use the "homophonic naming method".
Using the homophony of names is a relatively common method, and it is also a method that has been used by many people in literature, such as Cao Xueqin.
Homophonic names can be chosen based on the character’s personality, identity, background, seniority, character design, etc. according to the overall needs of the novel.
For example: the name Chen Fei is homophonic to Chen Fei, the red dust flies away, and the character is romantic and unrestrained.