Book 1 of The Tyrant's Grasp

A little over 1,500 years ago, the ancient wizard Tar-Baphon - slain by Aroden millenia earlier - returned to Golarion as a powerful lich known as the Whispering Tyrant. He ruled an empire of the dead, bringing much of central Avistan to heel for five centuries before Taldor finally launched the Shining Crusade to halt his conquests. The paladins of the crusade carved a slow, deadly swath into the Whispering Tyrant's forces and summoned Aroden's herald, Arazni, to finish her patron's work. But Tar-Baphon had grown more powerful on stolen secrets and borrowed glory than anyone suspected, striking the archon down and throwing her lifeless body before Taldor's armies.

The paladin's resolve would've faltered and the crusade failed had it not been for the paladins Iomadae and General Arnisant being able to rally their forces and succeed in imprisoning the Whispering Tyrant in his stronghold of Gallowspire. The Great Seal was constructed to ensure his imprisonment would bind him beneath his fortress forever. 

But now...the Seal is being weakened, and the Tyrant, his rage cooled by millennia, has a plan...

(Glossary will be provided first so that this doesn't read like IKEA instructions)