A brief description of the manhua I Became a God Devouring Souls at the Crematorium:
To raise money for his sister’s medical treatment, Lin Yu has no choice but to take a dangerous job as a cremation worker at a high-risk crematorium. There, he accidentally unlocks a Soul-Devouring System — granting him the ability to absorb the souls of cremated warriors and monsters, gaining their memories and abilities in the process. Using the soul of the first warrior he absorbs, along with the souls of two mutant beast corpses, he acquires body-tempering techniques and combat skills far beyond those of any ordinary person — and uses that power to rewrite his fate entirely.
