The Sixth Saint Astraea, or simply Maiden Astraea, is the final demon boss in the Valley of Defilement. Of all the enemies encountered, she is the only one who is believed to be not thoroughly evil. In contrast, she is benevolent and gentle, uninterested in bloodshed. In the boss fight, she never attacks the player, who instead must fight her knight, Garl Vinland. Ironically, her soul is often referred to as the most impure soul.
Astraea is a woman of peace, who came to Boletaria believing that she could sway the demon's through her gentle nature. Whether or not she actually lost her soul is undisclosed, but it is implied that after failing, she fled, grieved, into the swamps. Here, she stayed with her faithful bodyguard, still a faithful follower of her religion, but doubting God's kindness. She took it upon herself to help those she could, and aided the depraved ones like a mother. To protect her new charges, Maiden Astraea poisoned the swamps, bringing forth toxic beasts that roamed the valley.
When the player arrives, Vinland, who is sitting on a pile of enemies conquered, departs with Maiden Astraea giving him one final blessing. As the player descends into the valley, she repeatedly and gently asks the player to leave, that "there is nothing here for you to pillage and plunder." If the player chooses to bypass Vinland and shoot Maiden Astraea with arrows, Vinland will become passive and morose. If instead you challenge Vinland, Astraea will kill herself, leaving the Pureblood Demon's soul behind.