The impression I got - and this is just speculation - is that Pat originally intended for a 20/30-episode storyline, to be painted by Langley, in 1993-94, and the three-part "Hammer of Warlocks" short story was all that came of it. You'll note that, like the early episodes of "The Horned God," it recaps what had come before, for the benefit of potential European readers who'd be meeting the character for the first time, just as "The Horned God" brought Slaine to a whole new audience in France and Belgium.