Unseen

Villains who prefer to remain hidden or are not actually seen up until a certain point. These come in two types which often overlap: villains who are not or have yet to be seen such as Blair Witch and Evolt or villains who lurk in and strike from the shadows such as Herobrine.

These villains tend to be either very dangerous or very mysterious. Sometimes both, given that they lurk in the shadows and can use their minions for their own dirty work. Some villains prefer remaining hidden away from others, and it often allows the story to build up to the chilling moment when they appear in the flesh (i.e. All For One). It can also allow for other characters to tell and mention their supposed evil deeds without said villains making an actual appearance (i.e. Demon King (Konosuba)).