Rave Master Vol 32

From the Tokyopop edition

Elie and Haru finally beat Lucia's grandfather, Shakuma. But when Lucia finds out about her grandfather's defeat, she summons the Four Demon Kings to start the final phase of destroying the parallel world! Will Elie and Haru be able to complete the Rave sword and stop the apocalypse? It's a race against time as they attempt to harness the power to battle Lucia's mighty army!

Source: Anime News Network Encyclopedia