Sin Eater, School Beauty's Kind

A modern youth transmigrates into a bizarre cultivation world, bound to the Divine Punishment System. He grows stronger by devouring sin and hunting strange beings. Disguising himself as the most ferocious of these anomalies, he hunts even more powerful prey on the edge of a knife. As his body becomes increasingly corrupted by the strange, he attracts the attention of righteous cultivators and official forces. He then establishes his own intelligence network and makes initial contact with various factions.