Complete Monsters (also known as Devils in Person) are the most evil and worst type of villains, the villains who are pure evil. And for this kind of villains, doing evil for them is as natural as breathing. These villains must have no redeemable qualities, commit atrocious actions and show no regret for their crimes, and commit actions that are extremely unforgivable. Most, but not all monsters cross Moral Event Horizon as they do atrocious acts. If these primary monsters do not die or get killed by protagonists in the end of the story or novel or series, it can lead to sad or bad ending. However, some of these monsters can lead to downfall as Damned Souls after they die or are defeated by heroes. They are the direct opposite of Pure of Heart as heroes are incorruptible.