Walkthroughs for custom maps.

This isn't a bug, it's a feature! Creating heroes of level 6424 is quite a common practice. I once encountered a Tazar with such a level – no stack of units could deal more than 1 damage to a single skeleton (if I remember correctly), and it seemed like magic couldn't be used either. I defeated him with a mace from an Ifrit. It's a good thing the author didn't replace the skeleton with an energy elemental – you can't damage that with anything, not even a fire shield or a gorgon's gaze. Only the acid breath of rusty dragons could do it, but there weren't any of those on the map.