If Zeldor is that unstoppable then how about we all throw as much as we can at him for a few turns, then if he still holds the isle we can safely declare him the winner.
Lol, my mages decided it was necessary to cast arrow fend, curse of stones, fire storm, earthquake, warriors of muspelheim, living water, living fire, mass regen, army of gold, army of lead, weapons of sharpness and some other stuff to kill one! anathemant warlock. At least he had some fireworks before death.