Firestorm

Firestorm is a tome available from two known locations - the River Styxx and the temple within Shayol-Ghul. The tome is a random load on an imp that wanders on the River Styxx. The tome from Shayol-Ghul loads on the 2nd demon inside the temple. The 2nd demon is a fierce opponent with necromancer spells and warrior skills often requiring a brave group of adventurers.