Zhao Youyue took control of Chu Luoxun, who had already acquired both "Brilliance" & "God of musical's blessing."
After possessing her, Zhao Youyue noticed a hidden setting for Chu Luoxun that had been set by the author Leng Zi. Before a performance, Chu Luoxun has to chant a sentence in French, "Dieu de la musique, s'il vous plaît écoutez mon appel," (which translates to God of Music, heed my call) to relieve her of any worries, so that she would be able to perform flawlessly.
It was not clear why she had to chant in French, maybe that would make her cooler, or it was just some adolescence's delusion.
Chu Luoxun actually knew French, probably due to her family background, but Zhao Youyue did not set these details, she only can establish a character's abilities and characteristics.
It was quite amusing to discover this hidden setting, some people in reality would do the same, saying some specific sentence or words to keep their cool.
