In a world where soul pets and Beast Masters exists, As a normal boy from our world，Lee Xingyun finds himself mysteriously transmigrated into the body of a second-year high school student.

After discovering that he is now a part of a narrative that closely resembles a protagonist's backstory, Lee must navigate this unfamiliar world and its complexities.

As he unlocks the powers of the Soul Appraisal system, Lee is granted a unique opportunity to choose his first soul pet egg. Amidst a sea of low-level Servant Level pets, he stumbles upon two high-level soul pet eggs—the Flame Spirit Tiger and the Green Cloud Bird. Thrilled by the Flame Spirit Tiger's potential and its mysterious evolutionary path, the Dark Abyss Heavenly Devil Tiger, Lee's heart is torn between these two formidable creatures.

Embarking on a journey of power, friendship, and destiny, Lee Xingyun faces the challenges of the Soul Pet University, where each student's soul pet will become the foundation of their evolution into a Beast Master. Along the way, he forms bonds with fellow students, mentors, and mysterious individuals who hold secrets about the ancient history of soul pets and their connection to a hidden power.

Join Lee Xingyun on his quest to unlock the full potential of his Flame Spirit Tiger and unravel the secrets of the Dark Abyss Heavenly Devil Tiger.

Will he uncover the mysteries behind the Dark Abyss Heavenly Devil Tiger and fulfill his destiny as a true Beast Master, or will the challenges of this new world prove insurmountable?

C304 Sin