Yuan's Heart Demon

"What kind of trial is this?" Meixiu mumbled in a dazed voice as she watched Yuan defeat the demon multiple times.

"By the looks of it, this trial appears to be some sort of heart demon trial." Feng Yuxiang said.

"What is that?"

"In essence, heart demons are stress— a negative emotion that looms in the deepest part of one's heart. When someone experiences a traumatic event or something terrifying, there is a very high chance that whatever happened becomes their heart demon,  and these negative emotions become a mental barrier which hinders their cultivation from advancing." 

"Heart demons are very common, and they exist in almost everyone, including mortals, but they affect cultivators the most. Heart demons can be formed by any kind of stress if it's strong enough. Fearing that you'll never find love… Being insecure about your appearances… Worrying about not being able to return your debt… Even one's obsessions can also become one's heart demon."