Alice owned the first B-rabbit, as Oz a pair of twin dolls. Core of the Abyss destroyed one of Oz's bodies by giving him memories of Lacie to give to Jack. Jack saw these memories and went over the edge with grief. Believing Lacie was still alive, he tried to deceive Alyss into making a chain for him, which she does with Oz's last body. On the day of the Ceremony, Jack meets Oz and they forge their contract. Oz slaughters the Baskervilles and Glen, however Alice has some type of psychic connection with Oz, so she figured out what was going on, and acted like her sister to fool Jack into telling her everything. Then she revealed herself and scolded him for hurting Oz, Jack tried to force her sister to come to Alice's body, and Alice stabs Jack with scissors, and declares that she'll never let him do this. She talks to Oz and then stabs herself to death. As she dies, the Intention weeps over her and apologizes for hurting her, but says that as long as Jack lives, she'll keep yearning for him. So she (The Intention) wants to use Oz to destroy her memories. She comes back to Earth using Alice's body, but Jack distracts her, so Alice also joins her, but as a spirit, she fuses with Oz's body to both sever his contract with Jack and save him from suffering. This throws Oz into Jack's body. However, the Core will not let Alice use that power, so she winds up using energy against all four of them. This causes Jack's body to deage, and Alice, Intention and Oz all lose their memories. This winds up with Alice being thrown into Abyss by the Core and thus, her thinking she was the B-rabbit, because she didn't remember anything. Hope that answered it.