
Each character has two to three names.
An intimate name, a common name and sometimes a title. Or many titles.
In the main characters case, he is Wei Ying (this is what his family and friends would call him), Wei Wuxian, (what strangers or people in more formal settings would call him ), and Yiling Partiarch (his title).
Our ML is Lan Zhan, Lan Wangji, and Hanguang-Jun.
For a comprehensive list (and some potential spoilers) vist:
https://exiledrebelsscanlations.com/gdc-character-and-sect-guide/

What bothers me is that, in the novel at least, "Jiang Cheng" is almost exclusively used for that character. "Cheng" is supposedly the intimate form according to the list, which means just about everybody calls him intimately.
Now it could just be that since the narration is almost exclusively from Wei Wuxian's perspective, he doesn't bother with jiang cheng's common name in his head, having been raised like brothers, but the other cultivators also use his intimate name. So it bothers me. Especially when there's that uber rare ocassion they do use his common name.
I'm so confused with the name ( ̄∇ ̄")