Long before the formation of Prythian, and long before the Cauldron and the Mother, Koschei lived in a different dimension with his siblings: Stryga and the "Bone Carver". He, alongside his siblings, fell into the world and due to their immense power, were worshipped by ancient fae. Koschei and Stryga loved the attention, though the Bone Carver did not enjoy it as much.
A female fae warrior tricked Koschei and managed to diminish his power. She confined him to a lake on the Continent, where he stays trapped. The same warrior confined Stryga to the Middle and the Bone Carver was sent to the Prison.
- In Slavic folklore, Koschei is an archetypal male antagonist, described mainly as abducting the hero's wife. He is also known as Koschei the Deathless. Koschei cannot be killed by conventional means targeting his body. His soul (or death) is hidden separate from his body.
- A Court of Wings and Ruin (Mentioned only)
|Amarantha · Amren · Azriel · Cassian · Elain Archeron · Feyre Archeron · King of Hybern · Lucien · Morrigan · Nesta Archeron · Rhysand · Tamlin|
|Minor and supporting characters|
|Alis · Andras · Beron · Bron · Cerridwen · Clare Beddor · Cresseida · Devlon · Eris · Graysen · Feyre's father · Hart · Helion · Ianthe · Isaac Hale · Isaac Hale's wife · Jurian · Kallias · Keir · Mercenary · Miryam · Mortal Queens · Mrs. Laurent · Naga · Nuala · Unnamed Summer Court Faerie · Tarquin · The Bogge · The Bone Carver · The Suriel · Thesan · Tomas Mandray · Varian · Weaver|
|Aunt Ripleigh · Dark Mother · Drakon · Feyre's mother · Ianthe's father · Ianthe's mother · Ianthe's sisters · Miryam's father · Miryam's mother · Mother · Rhysand's father · Rhysand's mother · Rhysand's sister · Nostrus · Queen of the Black Land · Tamlin's mother · Tamlin's father|