Black Cat Taoist

Gu Ying traveled through time, and the object was: On the foggy mountain known as the Yunzhou Demon Cave, The Bone-changing Immortal Lord, known as one of the Eighteen Demons, A cat in hand. After accidentally ingesting the demon refining pill, Gu Ying, an ordinary little black cat that should not have transformed into a human, turned into a demon cultivator who could switch forms at will. From then on, he used the body of a cat to wander around the foggy mountains when he had time, but found that all the demons had their own agenda. Gradually, out of the devil's cave, Infernal Affairs begins. PS: This book is also called "I am an undercover agent in another world" and "What evil intentions can a kitten have"