Shades are the beating hearts of the soul, the part that makes people process complex emotions like love and create empathy with others. Shades might make you feel emotions to their fullest, but, if traumatized, it will make you feel agonizing pain.
Little is known about Shades, and most information is heavily related to religion. Shades are not a common knowledge among students, but may be at least told about by the time a Brakebills student graduates their course.
Described by Martin Chatwin as "a tiny beating heart" in the very center of your being, Shades are what makes you feel like the most intense of emotions, including pain seems as though it would "burn you 'til you're nothing", but Shades are also there for love, as they are what makes people 'human'. Shades are heavily connected to an individual's sense of right and wrong, and the emotional connection of the person to their morality. It allows the person to process complex emotions and connect to one another.
Upon removal, a Shade goes to the Underworld and into the Elysium providence for their eternity. For an individual to rest in peace they must have their Shade, though this may be arranged post-mortem.
Outside of a person, a Shade's appearance is a younger version of themselves.
One can remove their Shade out of choice, but in some special cases, individuals may lose their Shades through magical circumstances. While they won't die, their emotional capacity is nonexistent: they will be unable to truly feel or have empathy towards others, and thus become less hindered by moral repressions. They see the world in a very logical and straightforward way, willing to do anything to accomplish their goals, abandoning their original personality.
Julia Wicker, upon realizing what being Shadeless meant to those around her, had to consciously reflect her actions based on her memories of emotions and feelings alone. Many Niffins are bloodthirsty as a result of their lost Shades.
Shades can be removed in pieces or as a whole. The slightest removal will evoke a significant change in a individual's personality. Shadeless individuals are able to hold the Shades of others, as with Julia putting Alice's Shade inside of her briefly. In the Underworld, Shadeless people have a large hole in their abdomen that slowly closes. The more that a person goes on without a Shade, the harder it is for them to regain it, and eventually, once that hole in their soul closes, they'll be unable to return to their original selves.
Individuals with No shadesEdit
- Martin Chatwin - By choice. 
- Julia Wicker
- (Book) as a sacrifice to a god.
- (TV) as a complication of an 'exorcism' involving her unborn demi-god fetus, ultimately restored.
- Niffins - In the process of becoming a Niffin, an individual will lose their shade.
- A Shade can be equated to "the heart" of the soul
- Shades in the Underworld act as guardian angels performing minor miracles and live in Elysium
- Humans lose their Shades upon transforming into Niffins and cannot be reverted back without them
- Patrons of the Underworld have jurisdiction over the Shades in Elysium and can even bring Shades from the Underworld, as shown when Persephone reunited Julia with her Shade after vanishing with Reynard.
- This could be a reference to the more classical forms of mythology, with Hades being known to return the souls of the dead to adventurers like Odysseus.