[Marco making the most sense? It's the end of the world. But liking monsters is a family thing for him.]

Just because someone's not human doesn't mean they can't control themselves, eh.

In my world people tend to call anything with excessive strength or an ability no one else has "a monster." Fishmen, giants, devil fruit users. There are a few unthinking monsters, but they're more animals; just prone to relying on instinct, and even then I think the seakings or others are more intelligent than people realize.