Because of the mysterious nature of the Fair Folk, not much is known about the faeries of the Unseelie Court. They do not involve itself in outside affairs, such as the Shadowhunters or their Accords, and are not very interested in even trying to be in good terms with them. Their court is also said to be a terrifying place. Presumably because of this, Gabriel Lightwood referred to them as the nasty ones, most likely in comparison to those of the Seelie Court. Also, according to Sallows, Unseelie Court faeries do not like too much light.
In 2012 the Unseelie King used a spell from the Black Volume of the Dead to create a blight on the Unseelie lands which rendered Shadowhunter magic and seraph blades useless. A group of Los Angeles Shadowhunters later entered the Court to rescue the faerie prince Kieran, and discovered the blight.
- Much like Gabriel's reference to them as being "nasty," the Unseelie Court is often seen as the classification given to "evil" faeries; though since the Seelie Court has been known to be quite malicious, the Unseelie Court is usually seen as darker and more inclined towards unprovoked assault. However, the beings of the Unseelie Court are not always malevolent, but when an Unseelie faerie is forced to choose, they will naturally prefer to harm than help.
- The Unseelie Court is often considered to be the combination of the Winter and Autumn Courts.
- A hawk, a throne and a broken crown are the symbol of the Unseelie Court.