The hero(es) later stormed the Forgotten Tower. However, it was not enough, and the Blood Rose was slain.

From afar, she summoned simulacrums from the pool of blood the monstrosity resided in, to aid in its fight against the hero(es) that were attacking it. When Lakrii fed herself to the Blood Rose, her blood was apparently enough to finally fully revive the Countess. She ordered that they flee the Dark Wood before she decided they no longer could.

She was defeated, but the Countess was unperturbed, stating that the blood of her servants returned to her upon their deaths, so that even her foes' victories hastened her return. The Countess reappeared to her foe(s) in the Fetid Swamp via some form of magical projection, where she ordered that Vassarici kill them. Yet even this was not enough to restore the Countess fully, and she ordered the Bloodsworn to hasten their efforts, lest they lose her favor. The Bloodsworn themselves razed the town of Blackstone to the ground, gathered the blood of every man, woman, and child, and through some kind of ritual, infused their mistress with it. As long as it continued to feed her blood, the Countess would not die. The roots of the Blood Rose ran through the Dark Wood, feeding her with blood spilt within the forest. The Bloodsworn set about collecting blood for her in an effort to restore her to her former glory. The strongest of the Bloodsworn remained in the tower, acting as her protectors. Furthermore, a Worldstone shard came into the Countess's possession, which she wore around her neck.

Six years later, the Countess was resurrected by a group of cultists called the Bloodsworn, who served as her followers.

Diablo 2 countess immunities