"Like colours, but if colours hated me." aka The Entities

[epistemological]

So in the world of The Magnus Archives, there are what's known as 'Entities', things made out of the fear that exist outside of the bounds of reality that occasionally poke their fingers in and meddle with the world. They come in a full 'spectrum' with some generally accepted 'shades' that have titles and forms and potentially some manner of gender, with lesser and less specific sorts of fears filling up the spaces in between.

Each entity seems to have places of power, avatars, "Leitner" books, and creatures, with some entities also having rituals designed to bring the world into closer alignment with them to allow them to enter reality properly.