|“||Hey, can't you hear the voice? The voice telling us to kill all of mankind?||”|
In the manga
During the attack on Maple House, Barbara and the other Mariko clones appeared to go above and beyond their controls to save the wounded Nousou. Feeling parental towards her while recovering in the hospital, he removed and deactivated her mind-control device. She was set free, but, shortly after, killed a friendly nurse who tried to help her and dumped her severed head in Nousou's lap. She let him know in no uncertain terms that she hated him for his treatment of herself and the other Diclonii. Nousou gave a brief apology for this before she decapitated him.
Able to sense the presence of other Diclonii, she pursued Nana and found her with a grieving Kurama. Angered that Nana would be so close to a human, she was at first stopped from killing him when Nana said that he was not her real "Papa," but Barbara's. Kurama believed her to be Mariko and told her he loved her. Barbara stated that having been grown and raised in a lab, she felt no connection to him and in fact wanted to kill him all along to rid herself of any human connections. She and Nana fought, with the latter outmaneuvering and even overpowering her. But Nana finally found herself being overwhelmed by her opponent's ruthlessness, as she took Kurama hostage. Breaking out of his fog and at last realizing that Mariko was dead, Kurama shot and killed her before she was able to kill Nana. Barbara, at times, seemed to be responding to Nana's pleas to take care of their 'Papa,' and Kurama felt that she could have deflected the gunshot, but she chose not to.
Vector Range: up to 10m (according to Nousou)
Strength: on par with Nana's
Vector Special Ability: unknown; presumably similar or identical to Mariko's
Kills: 2 confirmed (unnamed nurse, Nousou)