From DivNull RPG
The Player's Guide, pg 87, claims "this unholy manuscript serves as a guide to damnation and damnable power (see BoTC, p.22). Every copy of the book is different, all imperfect reflections of the original tome that has not yet been penned. But all winding and crooked paths lead to Malfeas, and every copy leads its reader toward resplendent slavery or utter madness. A copy of The Broken-Winged Crane is an Artifact •••••, possession of which means certain death in the Realm and much of the Threshold. Mere rumor of the book's existence can doom a sorcerer to death or inescapable disgrace."
The Lineage of the Broken-Winged Crane
Stag possessed (using God Ways) a copy of this book and discovered the following about it:
This book is one of a race of first circle demon known as geranosi. All individuals are different, but all appear as books and have a similar purpose, though slightly different contents. This particular book sought a reader worthy of understanding its knowledge without going mad, who would then be introduced to the books creator, whom it loved as much as any demon can love. Such an offering would make the book complete.
All geranosi are created by an undulating storm of jet-black ink and feathers, a second circle demon named Gruidtsuru, the Aviary of Ink Wings. Stag briefly became lost in with fascination in the writing patterns of Gruidtsuru contained in the book's memory. Clearly this creator demon knows something, maybe everything.
Gruidtsuru is the wisdom soul of of a third circle demon who appears as woman with jet-black skin, wearing robes of pale silver, whose eyes glimmer like the moon. Strands of her ebon hair glow white and a rat's tail trails from the back of her robes. Thunder cracks when she enters the mortal world and torches and other lights instantly go out in her presence. This is Erembour, That Which Calls to the Shadows. She carries a long silver horn curved like a ram's and when she sounds a long slow song, it fills the hearts of those who hear it with a melancholy attraction to the darkness and calls the people of Malfeas out to make blind revel and follow in the path of her master.
Erembour both serves and comprises one of the souls of a Yozi who is the shadow of everything that has ever lived. While Malfeas has no night, this Yozi, the Ebon Dragon, occasionally blots out the sun and the streets of the Demon City clear, save for those who hear the call of Erembour's horn.