— 1 hour ago | Karakura Town, Tsubakidai, Matsukura Hospital site
Why am I alive? This thought was on the mind of the masked female arrancar, Roca
PARAMIA, as she stood on the roof of an abandoned hospital. Her master, Szayelaporro, had told her, "Don't think you have any will of your own. When you aren't useful to me, you are the same as those roca (rocks) over there. …Ah, that's the perfect name for you." That's how he had named her — a spider-type adjuchas — right before AIZEN had turned her into an arrancar. She was a tool and yet she had a "self". Why was she alive? Roca was the result of Szayelaporro's experiment in which he intertwined countless souls together and artificially created a menos grande. Her life was supposed to end as foil against Kenpachi KURUYASHIKI, but he had spared her. She figured Szayelaporro would end her life anyway. She felt relieved. This meant she would no longer have to think about her own existence. But Szayelaporro had gotten a new idea after watching KURUYASHIKI's death. He would continue to experiment on her for another 200 years. Her body would be chopped up endlessly. He eventually gave her anaesthesia when he grew tired of her screams.
In the end, she got a new power. The power to connect with all matter via her negación threads, and to share spiritual-energy and information. She felt happy to be useful to her master. But it didn't last long. After Szayelaporro perfected his own ability, Gabriel, he no longer had any interest in Roca. She had once again lost her reason of existence. In the end she did chores and worked as nurse for the other arrancars as Szayelaporro's fracción. She had met all the other Espada, but none of them had needed her either. When she worked as nurse for Yammy, he smashed her head in. She should've died. By becoming an arrancar, she had lost the hollow ability of High-Speed Regeneration. But what laid at the heart of her ability was "Backup" — external storage. Duplicating her own soul and memories, she could pull those from her body whenever something happened to revive herself. As part of his research on immortality, Szayelaporro had connected himself to her "threads", constantly backing up his memories inside her. Or, to be more exact, he had dispersed information to all matter in Hueco Mundo (stones, quartz trees etc.) via her body. But then he achieved Gabriel. He didn't need her backups anymore to resurrect himself. Even so, he didn't kill her. He let her exist as some handy memo pad.
Through countless experiments, Roka had threaded her soul with a large part of Hueco Mundo. When she was about to die from getting her head smashed in, the information she had dispersed in the stones, quartz trees and the palace's walls regurgitated via her threads, regenerating her body, soul and memories. After a long time, her broken body was reconstructed. And she knew. While she had been busy being put back together, AIZEN had left Hueco Mundo and Szayelaporro had been killed by a soul reaper. Without any purpose, she wandered and wandered. She also visited Karakura Town, the town which her master and AIZEN had often monitored. But she found no purpose there either. Her negación threads connected with everything around her, automatically. That's why she'd frequently join her soul with the matter of the World of the Living, becoming faintly visible even to humans without reikan. She was empty. So empty. And then she heard her master's voice, — "Can you hear me, fool?"
She didn't know that her negación threads had kept sending information about Hueco Mundo into her while she was restoring herself. And so, she had continued spinning thread, creating her master's persona in her giant network of stored information. The voice talked about needing a new body. But he wanted a suitable body. And so she returned to being Szayelaporro's tool. Freedom meant nothing to her anyway. She wanted purpose. Back to the present: A hero has appeared before her. She could run, but this man wasn't a soul reaper, quincy or hollow — the things Szayelaporro had told her run away from. She didn't move. She didn't talk either. But the man grabbed her hand and said, — "Beautiful lady, rest assure, I am your ally. Please tell me, Don KANONJI, the reason behind your sad eyes.".