This is a bit late in the currently airing schedule but...

I think this is the most accurate depiction of a psychopath I have seen in K-dramaland

Neuroscientist James Fallon gives very interesting insights into the facts of this genetic presentation https://www.smithsonianmag.com/science-nature/the-neuroscientist-who-discovered-he-was-a-psychopath-180947814/

So often in dramas, worldwide, they're presented as completely evil, but that's not quite right.  Cafe Minamdang at least shows how people can be highly successful and functional (even though it's used to go completely haywire, late in the show)