The Bad Guy Takes over the Guild, and the Top Killer Captures Cats and Dogs

You mean the top killer who kills countless people volunteers in the community? Giving an old man a pat on the back in a nursing home? Telling stories to children in an orphanage? Volunteer at a hospital? The bad boy is forced to inherit the killer company, gets involved in humans and monsters, and reveals the dark side of the world. "Why are you giving me these missions to catch cats and dogs again? After all, I am also one of the top fifty killers in the world!" "That's pretty good of you. People like us are tasked with accompanying our children to the amusement park."