Wu Chang didn't change his own nickname, but rather the nickname of the clone in Shadow-Facing Face.
The clone has all the player's permissions, which naturally includes having an independent nickname.
As part of him, he can freely choose which nickname to display on the leaderboard.
After being reminded by Divine Tongue and the fluctuation of killing intent, he checked the forum and found out that it wasn't unprecedented for players at the top of the leaderboard to use nicknames for advertising.
However, those who used to do such things were players ranked in the top ten of small leaderboards, such as the proficiency rank for Life Skills.
The leaderboards where ranks were fought for through sheer strength are occupied by core players of major forces and don't need such methods to earn money.
Especially the speedrun leaderboard, it's the one that showcases individual ability the most, and no one has used it for advertising yet.
