Slayers Volume 8: King of the City of Ghosts

Without warning, Phiblizo appears and attacks Chaos Dragon Gaav. He kidnaps Gourry by using the Sword of Light and taunts Lina to join them in Sairaag, a city that is now a barren wasteland with only a single Flagoon since the demon's resurrection. But Lina doesn't have time to think about the consequences -- she has to settle things with the Hellmaster once and for all!