The apprentice's master, who died after unleashing his deadly spell, was being spied upon by the Netherworld's ruler, Vissiluth, who is now intent on conquering the world of the living. It's once again up to this apprentice to stop him, by battling this demon.
The NPC wizards are now considered to be Vissiluth's lackeys. They are all based in a city just before Vissiluth's seat of power. After the enemy wizards are vanquished, the apprentice takes an underground passage to reach Vissiluth's citadel. After the apprentice destroys the citadel, Vissiluth emerges and the two do battle. Upon emerging victorious, a volcano spews out mana in all different colours.