(BLACK BUTLER AU)

Bizarre Dolls are created due to illegal experiments with humans, conducted by the elite doctors of Karnstein Hospital. But in terms of accuracy, they are the consequence of the addition of fake records to their Cinematic Records, which prevents the circumstance of death, i.e. the "End" mark. The body mistakenly believes that it is still alive and starts moving again without a soul. All living beings instinctively try to fill up whatever they lack, and the same goes for Bizarre Dolls; in order to find a "soul," they will try to open up the bodies of the living in order to settle the balance of the never-ending Cinematic Record. And for that purpose, they are able to pursue after souls without the methods of perception.

The rightful creator of the Bizarre Dolls is the Undertaker and, in order to resuscitate them, he added fake records to their Cinematic Records. However the Bizarre Dolls are more advanced now; When they die, humans do not only recall their pasts, they also carve and mourn the futures they could have had. Undertaker found a method to extract those episodes of longing and desire and attach them, instead of the fake records, to people's Cinematic Records. By doing so, the resulting Bizarre Doll will be "infinitely approaching a living human" as they run on their own "future forecast." However, the current success rate is rather low but The Bizarre Dolls created with this new method are often indistinguishable from humans as they retain their consciousness, senses, and ability to speak; they are also not driven by the instinct to obtain a soul anymore. These Bizarre Dolls are able to fool demons as well, though they might feel a slight sense of discomfort in their presence. But even the evolved Bizarre Dolls cannot maintain their biological functions, like their circulatory systems, as they are still nothing but reanimated corpses. They, thus, need regular blood transfusions

You're a perfect Bizarre Doll that ran away Because Undertaker and Sebastian are fighting over you