Oh the heroes will either be given amulets of health, hardened skin, maybe a reincarnation ability, or something similar of they are encountered in a boss battle type situation, also when you go up against Dioneve she simply raise a ton of fallen soldiers as undead to destroy your base and you, your goal is to destroy several of her bases along with the hills of bones within them and ye once you get to her final base you have to destroy her bodyguards and her, and although she does have relatively little hp, the battle will be hard because of the various other factors, plus there might be some surprises once you actually get into her base (or fortress or whatever she's in)