Return of the Runebound Professor (Book 6)

Dragged into the homeland of the demons by Wizen, Noah, Moxie, and Lee have decided to take an entirely unforeseen path to their solving problems: take control of Treadon’s underworld and overthrow its Demon Lord. When facing demons leagues more powerful than any mage in Arbitage, the only way forward is through sheer strength or an impressive amount of confident bluffing. Fortunately for Noah… he’s not half bad at either of those. Never before has he been able to use the full might of his magic completely without restraint. Now, he doesn’t have any other choice. With a small but growing army of demons at his back, Noah sets out to conquer the Damned Plains and bring Wizen’s plans to a halt so he can return to the students waiting for him back in the mortal realm… And may the gods have mercy for anyone that stands in his way.