Ah. It's been a while since I've last read this. Seems like it's on Hiatus though...
Aside from the stereotypical large tits count, the way the MC operates is a breath of fresh air in isekai. The way he "fights" is different, because, you know, he's a pest exterminator.
As for normalizing slavery that the previous comment seems to have issues with. Slavery is incredibly common for the fantasy genre. It was also incredibly prevalent in the real world, so I'm really not seeing the problem with the nature itself appearing in writing. I do have problems with the trope that slaves feel indebted or ingratitude towards the "kind" masters, IE, the main protagonist. This stems more from my personal stereotype that slaves should feel more negative emotions towards their masters as a whole, regardless of sincerity. Simply put. It's hard for me to imagine. I suppose if you've been a slave for a majority of your life, receiving kindness instead of violence for once can shift your perspective? I don't know.