Von Keiner: Scourge of the Skies!

From publisher blurb: AN ASTONISHING AIRSHIP! VICIOUS VALYRIES! A TEUTONIC TERROR! The mysterious scourge of the skies, and a self-declared "citizen of the air", Kapitän Nikodemus von Keiner embarks on a reign of terror, striking the nations of the earth with no warning! A night-black airship appears from the clouds, blasting the terrified cities below with tremendous bolts of lightning. Who are von Keiner and his Sky Witches? What do they want? Who can possibly stand against them?