The Unforgiven in Shinigami
Las Noches, main hall.
Darkness shrouded most of the hall, and the floor gleamed with a cold, bluish-green light. Aizen leaned back in the lone stone chair, his cheek resting on his hand and his eyes closed as he replayed the battle footage sent back by the Reiatsu Recording Bug.
He let no detail escape him, from the course of Nnoitra's battle to Shiraishi's moves.
After a while, Aizen opened his eyes. A faint smile appeared on his face as he murmured, "Interesting. Truly interesting. It's been a long time since I met someone who interested me this much.
"Shiraishi, just who are you?"
There was the barrier of air that blocked attacks, the ability to pass through his body, the wind wall that nullified Gran Rey Cero, the tornado that could sweep Nnoitra up, the sudden doubling of his Reiatsu, and the technique that could still cut away Hierro after his Reiatsu returned to normal.
Everything about Shiraishi was different from the Zankensoki Aizen knew so well.
It wouldn't be right to call it a fusion of Zanjutsu and Kidō, either. He hadn't detected even a trace of Kidō in the wind wall.
The battle footage reproduced by the Reiatsu Recording Bug was an immersive experience, a perfect recreation of the scene that made Aizen feel as though he had become Nnoitra and was fighting the battle himself.
The data was so realistic that he could even sense Reiatsu, allowing him to be certain of his judgment.
Of the abilities Shiraishi used, only one was a Zanpakuto ability.
The others had nothing to do with a Zanpakuto.
Nor were they the powers of a Quincy or a Fullbringer. They might not even have anything to do with the Soul King, the origin of all things.
They were beyond common sense, beyond his understanding.
Perhaps they had something to do with Hell.
Aizen was well-read and had an exceptional memory. He recalled that among the many documents Takehiko Tsunayashiro had stolen was one stating that no one could detect the Reiatsu of someone in Hell.
That ability to conceal Reiatsu fit Shiraishi's circumstances very well.
But throughout history, Hell had never released a single sinner, and Shiraishi's appearance did not fit the image of Hell.
Or perhaps it was the Dangai civilization theory?
A Soul Society scholar had once suggested that the Dangai contained many alternate spaces of varying sizes. Perhaps one of them had a civilization that lived apart from the outside world.
Aizen fell into thought. He enjoyed pondering the unknown, and even more, he enjoyed unraveling it step by step and drawing closer to the truth.
Unfortunately, as he explored, there were fewer and fewer unknowns left.
Until now, only the Hollowfication Experiment had been able to offer him anything new. Now there was Shiraishi as well.
Before he could sift through all the documents in his memory, a source of Reiatsu approached from outside the hall.
He raised his head and said gently, "Nelliel, you're back."
A female Arrancar appeared in the doorway.
She wore a skull mask resembling an antelope's skull. Her face was oval, with vivid rose-colored markings running across it, and her long, lake-green hair fell over her shoulders.
Her white clothing covered her completely from the neck down, yet it still couldn't conceal the magnificent sight of her chest. A sword hung at her waist.
"Lord Aizen, I'm back. Tier Harribel said she would consider joining us."
Nelliel gave a truthful report on the progress of her assignment.
"Mm, thank you for your efforts," Aizen said gently. "I believe it won't be long before our Espada gains another new companion."
Nelliel looked around and asked, "Lord Aizen, I think I sense a trace of Nnoitra's Reiatsu. Was he here just now?"
Aizen shook his head. "No. The Reiatsu you sensed was probably because the Reiatsu Recording Bug was attached to him."
"The Reiatsu Recording Bug..." Nelliel frowned slightly. If she remembered correctly, it was a product of that former Zero Espada's research.
"Mm. It can attach itself to others and collect battle data on enemies. It's a very convenient invention."
"Did Nnoitra die?"
"He failed his mission and was killed by the enemy."
Aizen gave an affirmative answer. "Are you sad?"
"No. It's just that, as his former partner, I ask that you leave his unfinished mission to me."
A trace of sorrow flashed through Nelliel's golden-green eyes. She had always wanted to save Nnoitra from despair, but she had never managed to do so.
The conflict between them stemmed from their natures and beliefs being complete opposites.
Nnoitra, who had always regarded himself as a beast, immersed himself in battle to numb himself. He believed the Hollow race had no meaning and could not be redeemed.
She was different. She did not consider herself a beast.
There had been a time when she turned from a human into a Hollow, lost her reason, and devoured her own kind without end. Even after evolving into a Vasto Lorde, the hunger and thirst in her heart remained unfulfilled.
But after she met Aizen, the unfinished Half Hōgyoku helped her transform into an Arrancar. She regained her reason and no longer needed to devour her own kind, and she could eat Reishi-based food from Soul Society.
She therefore believed she could be called a complete person, thinking and acting with human reason instead of repeating the savage ways of a Hollow.
The question of who was right had caused many conflicts between them. On top of that, they had been assigned to work together, so they had fought often.
She had even grown used to beating Nnoitra up every day before returning to eat.
"There's no need to rush. There will be plenty of opportunities later."
Aizen did not give her a direct answer. Captain-level Menos Grande appearing one after another would easily attract Soul Society's attention.
He had other plans for Shiraishi.
"Yes." Nelliel was somewhat disappointed, but she still obeyed Aizen's decision.
She held great respect for the Shinigami who had freed her from devouring her own kind. She also believed that Hueco Mundo would continue to improve under Aizen's leadership.
Once Hōgyoku technology matured, there would be more Arrancar, and Hollows that regained their reason would engage in less needless killing.
Perhaps by then, they could even plant some greenery in Hueco Mundo. Facing the desolate scenery of a sea of white sand all day had left her a little weary.
Aizen took a large crystal sphere from his robes and tossed it forward. "I'm returning to Seireitei to take care of some matters. If Tier Harribel arrives, you can use my Hōgyoku to turn her into an Arrancar."
"I understand."
Nelliel reached out with both hands and caught the unfinished Hōgyoku.
The technology for creating Arrancar was not yet mature. For now, only Vasto Lorde like her could become true Arrancar.
Menos Grande below the Adjuchas level could not become true Arrancar. They could only become Imitation Arrancar.
They looked much like Arrancar, but in reality, the difference was great. Imitation Arrancar could not use Resurrección, and their combat ability was far inferior to that of Arrancar.
Tier Harribel was a Vasto Lorde, so she would have no problem becoming a true Arrancar.
"You may go." Aizen waved his hand. He had different methods of controlling Hollows with different personalities: intimidation, enticement, lofty talk of dreams, or expressions of goodwill.
His method with Nelliel was to give her his trust and a wonderful dream, making her fight to the death for him.
"Yes." Nelliel bowed, clutching the unfinished Hōgyoku tightly as she vowed never to betray that trust.
Aizen rose, turned toward the darkness, and stepped into a Garganta leading to Soul Society.