I Want to Be in Diary of a Madman

After an unexpected discovery, a mud monster devoured and took over the body of a girl named Mo Ranse, disguising itself as Qingfeng Mountain's junior sister. While pretending to be the junior sister, it encountered its formidable but eccentric senior brother, who had been ordered by their master to find it. After discovering that he possessed a certain power, it had no choice but to keep up the disguise while waiting for a chance to steal it, or for the senior brother to let his guard down.

It knew that taking the power by force would be tantamount to courting death. Only perfect deception and patience could help it wait for an opportunity that might never come: the moment his power fluctuated, the instant his mind relaxed, the chance to strip away his power completely and claim it as its own