This Lexicon which is similar to the Shade Archive, one of the many items in the Kingdom Hearts universe, allows Zexion to steal power from others and create illusions at will (even though he can already create illusions, the illusions that he uses with the Book of Retribution are more powerful). He also uses it to ensnare his foes into another dimension.
It is unclear exactly what the pages of the Book of Retribution contain, but from what can be seen, it tells some sort of story and lacks a basic dictionary layout. The cover is a dark grey, embossed with three white, intertwined Nobody emblems. The back bears the outline of another Nobody logo. The spine of the book displays a Roman numeral for six (6), VI, along with the title "Hallucination: Another Side", superimposed over yet another Nobody symbol; in the North American and PAL games, "Hallucination" is replaced with "Ignes Fatui" (Lat: "Delusions"). Both "Hallucination" and "Delusions" allude to Zexion's attribute of "Illusion", and the "VI" on the book references Zexion's rank as the sixth member of Organization XIII.
- A book is a collection of bound paper containing written material or illustrations. All of Zexion’s weapons are lexicons—a type of book—and many are named after other types of books. "Retribution" is a synonym for "vengeance".