After Nelliel Tu Odelschwanck returned to her childlike state, Kurotsuki Renya did not immediately dismiss the matter. On the contrary, there was still something he needed to confirm.
He looked at Nelliel thoughtfully and asked,
"When you return to your original form… does your Zanpakutō manifest automatically?"
This question had always intrigued him.
In her diminished state, Nelliel did not wield a blade. Yet the moment her true form was restored, a Zanpakutō appeared in her hand as if it had always been there.
Nelliel smiled gently.
"That's right. This sword seals my spiritual core. As long as it exists, my power is restrained. Once it is released, I can return to my true form."
"So that's how it works…"
Renya reached out and carefully examined the blade in Nelliel's hand.
At first glance, it resembled a Shinigami's Zanpakutō, but upon closer inspection, the differences were obvious. The spiritual structure was far denser, and the Hollow reiatsu interwoven within it was unmistakable.
"This is a seal formed from your fragmented Hollow core," Renya murmured. "Once released, it restores your original existence."
Many would question this.
If Arrancar could simply return to their Resurrección state at will, then what was the true purpose of Aizen Sōsuke's use of the Hōgyoku?
The answer lay in two key transformations.
First was the breaking of the Hollow mask.
In recorded history, only Coyote Starrk and Ulquiorra Cifer had naturally achieved mask fragmentation. All others Harribel included had relied on Aizen and the Hōgyoku to complete the process. When Harribel first encountered Aizen, she still wore a full visor.
Once the mask was shattered, an Arrancar's power increased exponentially.
As stated in the records of Soul Society:
A complete soul is whole. An incomplete soul becomes Hollow.
Hollows lack fragments of emotion and those missing fragments condense into the mask itself.
When the mask breaks, the suppressed energy is released.
Aizen's role was not merely destruction.
He sealed that liberated power into the form of a Zanpakutō, granting Arrancar a structure similar to Shinigami combat styles.
This explained the distinction.
The sealed state the blade carried openly was functionally similar to a Shinigami form.
The Resurrección was the act of reclaiming their original Hollow nature while retaining Shinigami-derived control.
Thus, Arrancar normally remained in the sealed state for stability.
Maintaining Resurrección constantly would result in excessive reiatsu consumption and loss of balance.
Only Kurosaki Ichigo, the Visored, and similar hybrids reversed the process mask first, Bankai later.
Arrancar followed the opposite path.
Renya handed the Zanpakutō back to Nelliel.
"Fight me," he said calmly. "I want to evaluate your current strength."
He needed to know whether Nelliel truly retained the power of a former Tres Espada.
In the original conflict within Hueco Mundo, Nelliel had only briefly returned to her true form and never fully clashed with Nnoitra Gilga, the Quinta Espada, before reverting.
Nelliel nodded without hesitation.
"But this room is too small," she said, looking around. "Where should we go?"
Renya recalled a critical rule of Las Noches.
Arrancar ranked below Cuatro Espada were forbidden from releasing Resurrección within the palace.
"Outside Las Noches," he decided.
They exited the palace together.
Waiting outside were Dondochakka Bilstin and Pesche Guatiche.
The moment they saw Nelliel restored, their eyes widened.
"Lady Nel! You you've recovered!" Dondochakka shouted.
Nelliel smiled warmly.
"Yes. And one day, you will too."
Pesche hesitated before asking,
"Then what are you and Lord Renya about to do?"
Nelliel glanced sideways.
"He wants to test my strength."
"…Good luck," Pesche muttered.
With a light step, Renya vanished in a flash of Shunpo, followed instantly by Nelliel. The two reappeared in the vast white desert beyond Las Noches.
Renya turned.
"Come. Attack me."
"Alright," Nelliel replied.
She drew her Zanpakutō slowly. The blade was short, black-and-white in coloration, radiating restrained yet terrifying pressure.
"I'm coming. Be careful."
She spun the blade casually
And vanished.
"So fast!"
Renya barely stepped back in time as the slash passed his face. Before he could counter, a palm strike followed.
Boom!
Renya's fist met Nelliel's palm.
The impact sent him flying backward, crashing heavily into the sand.
He coughed, rising quickly.
Her speed matched his own among the highest tiers for both Shinigami and Arrancar.
But her raw strength surpassed his.
Even after specialized training, Renya's physical power still did not rival Zaraki Kenpachi and Kenpachi himself had struggled against Nnoitra.
Yet Nelliel had overwhelmed Nnoitra with brute force.
"Is this alright?" Dondochakka whispered nervously.
"Lady Nel just sent Lord Renya flying!"
Pesche gulped.
"What if he holds a grudge…?"
"Shut up," Renya barked, overhearing them.
He drew his Zanpakutō.
"Again."
The next exchange was brutal.
Steel clashed, afterimages layered upon afterimages.
Nelliel vanished
The blade fell
Only to cut through an afterimage.
Renya's sword stopped at her back.
"You're too careless," he said quietly.
He stepped away.
Using advanced Shunpo techniques like Kongō Senpū, he could still keep up but victory would not be guaranteed.
Her current power clearly surpassed that of the Quinta Espada.
Then why had she lost before?
Renya already knew the answer.
At the time, Nelliel's mask had been deeply fractured. Reiatsu leaked continuously. After sustaining heavy injuries, her form collapsed.
Now that the mask was fully restored
Her strength had stabilized.
Renya looked at her.
"Return to Resurrección," he said. "I want to see your true form."
Nelliel nodded.
"Then… sing."
"Gamuza."
Her form began to change.
Renya watched closely, a knowing smile forming.
The true power of the former Tres Espada was about to be revealed.