The Empire of Lyzeille (Japanese: ライゼーリ帝国 Romaji: raizēri teikoku) is a country located in the western area of the mazoku barrier. It is bordered by Dils to the north, Ralteague to the east, and the Demon Sea to the south and west.
Significant cities and villages in Lyzeille include Atlas City, Sairaag, Telmoord, Crimson City, and an unnamed town referred to in the Tokyopop translations as Raizeel.
The events of the novels The Ruby Eye, The Sorcerer of Atlas, The Ghost of Sairaag, King of the City of Ghosts, Crimson Delusion, The Strategem of the Army of Dynast, and Demon Slayers! take place partly or wholly in Lyzeille.