One Punch Kills an S-Rank, and You Call This a C-Rank Paranormal Case?

The living have their own officials, and the supernatural have theirs! After transmigrating, Yi Yu became one of the supernatural officers, and he could copy the traits of all kinds of supernatural entities and people. But due to a series of coincidences, he never revealed his abilities in public and maintained a C-rank rating all along. Then one day, Xue Yan, the strongest A-rank supernatural officer, was attacked by an S-rank supernatural entity. At the critical moment, Yi Yu stepped in and killed it with a single punch... When Xue Yan learned that Yi Yu was a C-rank officer, she fell into deep doubt.