Why Sofi Stays
O-Ren belonged to someone, once. His name was Bill and he was the best thing that ever happened to her. Sofi Fatale, on the other hand, would have considered herself lucky simply to have monopolized her attention once in a while. It would be unfair to say that O-Ren Ishii had many lovers, because there was no one in all her life whom she had ever really loved. Say instead she had many hobbies, and all of them were destructive.
First she went for Vernita. She found a way. Then there was Budd; she left him after two hours in a hot tub and the two never mentioned it again. He didn't like that, but then that wasn't really the point. Even she knew better than to play with Elle, but that didn't stop her from a little exhibitionism in a convenient hotel window. It's probably a testament to the blonde's less than sound mind that the blood all over the walls were what she found most appealing.
Than there was the other blonde. Sofi appeared just as O-Ren was beginning to get somewhere interesting with her, and O-Ren's mind was much too sharp to miss the sparks that lit Sofi's eyes when they met, so of course she spent weeks detailing every event in her twisted, twisted affair, knowing full well how much it hurt Sofi. And though the French woman knew perfectly well that nothing O-Ren ever did was anything less than deliberate, she only loved O-Ren more. Sofi wasn't stupid. She knew O-Ren liked to hurt her. She liked being hurt.
But O-Ren wasn't as in control as she thought. As much as she was using the Black Mamba, the Black Mamba was using her. Sofi saw. Sofi saw, late in the night, when the glory of the kill hadn't yet dried on her face and the police were just catching wind. Every time, without fail, Bill would be there, waiting.
Sofi didn't blame him for it. He loved her, after all. But no one played O-Ren Ishii, even if she never found out about it, and so Sofi went to the pharmacies and the witch doctors. She wasn't an assassin, she was an administrator; she didn't need to actually kill anyone. If she wanted someone dead, well, it happened. As an afterthought, she poked tiny holes in every one of Bill's condoms she could find.
It took the blonde nearly six months to concieve, but when she disappeared and Bill found her there was no forgiveness, no joy, no honor in O-Ren's last goodbye.
Sofi looked at the blood-spattered bride, beaten almost unrecognizable and her belly swollen with the fruits of her betrayal, and spared only a moment for the distasteful creature before her before going back to the phones. O-Ren's honor had been saved and she saw no reason to dwell on the moment, especially with that charming Boss Koji on the phone.
O-Ren must have known what Sofi did for her, because even four years later when all the thrill had gone out of her side of the arrangement she persisted, fingers creeping along Sofi's thighs in the clubs, one hand for Sofi while the other held the phone, the wineglass, the brush. So convenient for her that the easiest way to keep Sofi coming back was to take no pleasure in her at all.
But all this is in the past. Right now, Sofi's got a vengeful goddess she has no hope of appeasing to her back with a sword she has no doubt could slice through the pillar her hand's on. O-Ren's looking down at her - no, she's not looking at her. Sofi has ceased to exist for O-Ren, and she knows in that instant that she has never mattered to O-Ren, has never been anything more than a momentary concern. The blonde... the blonde has O-Ren's undivided attention.
She stays even after she's lost the arm. She witnesses the extinction of the Crazy 88 with a sinking feeling, the deaths of Go Go and Johnny Mo, lost in her world of pain and abandonment as her blood pours out over the floor.
She can run. She can leave whever she can muster the strength to drag herself to her feet and stumble out the door. The blonde is otherwise occupied, ending the saga of O-Ren Ishii. Sofi knows enough not to be blinded by love, recognizes that there is no chance O-Ren will walk away from this battlefield.
She stays. And even she does not know why.