There are leaps in logic, the MC is a bit annoying and the ghost king seems to have inconsistent powers. Can he hear MC's thoughts? is he selective in what he chooses to acknowledge?
So far, either this is slow burn, or ghost king is firmly in the tsun half of tsundere. More like a himedere, tbh. also, most scenes of intimacy are rushed as hell, probably to avoid rating bumps?
look at its fanbase. And SVSSS has a really active one. Engaging! Cute! Amazing characters! enough freedom in plot for a hundred different AU's (which are also interesting)
http://bcnovels.com/the-scum-villains-self-saving-system/