Durst Manor a.k.a. The Death House
Durst Hall was first owned by Gustav and Elisabeth Durst. After some time, they began to use it as a gathering place to practice dark and evil arts, eventually birthing an evil cult. At first, membership was just a small yet nefarious circle of the Durst's closest friends, it slowly garnered more followers and influence and began luring unsuspecting visitors they would sacrifice in bizarre, arcane rituals and consuming them in cannibalistic banquets. Eventually, news of the Durst's morbid practices became known to the public, but the villagers, afraid to become involved with such abhorrent forces by some of the wealthier members of the town, turned a blind eye to the house and the debaucheries within it. With no resistance to keep them in check, the cultists expanded to even more lurid practices such as attempts to summon extraplanar entities, which met with one failure after another. Dismayed by these setbacks, the cult began to lose membership support as the activities eventually devolved into thinly veiled excuses for the Durst family to indulge in lurid fantasies.
Over the years, Gustav and Elisabeth gave birth to a daughter, Rosavalda, and a son, Thornboldt. The Durst children were locked and neglected within the attic, often for several days, their parents too obsessed with their cultish fantasies to pay their children any mind. As she approached the birth to her third-child-to-be, Walter, Elisabeth hired a nursemaid. Distracted by her debaucheries, it was no surprise she did not notice Gustav's eye wander to their new housemate until she discovered Gustav practicing his own affair with the young nursemaid. Whether it was from the shock or some other force, the boy was stillborn and Elisabeth seized on the opportunity to demand the nursemaid's life as sacrifice to appease the dark gods.
This pattern of dark behavior continued largely unchanged until, one day, Strahd von Zarovich arrived.
Awed by Strahd, Gustav and Elisabeth regarded him as a messiah sent by the dark powers they worshipped. They were drawn to him and begged for the gift of immortality, pledging their undying devotion if he would grant it, but Strahd dismissed them as unworthy. Determined to prove their worth by demonstrating their dedication to the dark powers, the Dursts continued their practices, eventually slaughtering a group of people that Strahd had brought to the realm for his pleasure. Annoyed that his playthings had been disposed of before he was finished with them, Strahd unceremoniously slaughtered the Dursts and the rest of the remaining cult members and imbued the Durst Manor with sentience and a hunger for fresh souls. Thus Durst Hall became Strahd's personal proving ground for potential playthings, and it has ever since been known to the villagers as the Death House.