How to kill Black Dragons?

If a hero has a high skill in Warfare, they can be used as cannon fodder. Also, don't forget about Defense!

Well, then you won't have to finish them off later =) I think we're talking about weakening them first, and then finishing them off. By the way, this tactic works well against Dragon Lords; they're tough, and I wouldn't let them join my army, unless I teleported them to the enemy's side. And if their troops are close to each other...:D it's going to be fun for whoever gets the roasted units.