Kurotsuki Renya's objective had never changed.
From the very beginning, it had always been the Hōgyoku.
Only the evolution brought forth by a complete and perfected Hōgyoku could push him beyond his current limits. Merely reaching the boundary of a Shinigami was meaningless such power was utterly insufficient against Yhwach.
To confront that being, one had to surpass the limits of a Shinigami altogether.
Even Aizen Sōsuke, after fully fusing with the Hōgyoku, had still failed to defeat Yhwach. Worse still, Yhwach possessed no discernible weakness. No conventional method, no orthodox power, could overcome him.
Fortunately, Renya was different.
He knew where his own shortcomings lay, and he also knew the solution.
As long as he obtained the Hōgyoku, he would gain the power necessary to oppose that monster.
To acquire the Hōgyoku, the first step was naturally Aizen's Hōgyoku. After Aizen's defeat, it had effectively fallen into Renya's reach.
The second was Urahara Kisuke's Hōgyoku, long sealed deep within Muken.
However, accessing Muken required a key, and that key was held exclusively by Yamamoto Genryūsai Shigekuni.
Even if one possessed the key, the method required to unlock the Hōgyoku's containment box was known only to a handful of individuals.
Renya had no legitimate reason to request access.
Thus, he waited.
And when Aizen was sealed within Muken when another Hōgyoku needed to be sealed alongside him, that moment became the perfect opportunity.
But stealing something of that magnitude required misdirection.
And for that, he needed Aizen himself.
After Aizen's capture, all the captains were instructed to touch his Zanpakutō, thereby dispelling Kyōka Suigetsu.
Yet there was a fundamental flaw in that method.
How could one truly confirm that the Zanpakutō each captain touched was genuine?
Only Renya could verify that.
And if Renya declared it genuine then it was.
Thus, the captains were never fully released from Aizen's hypnosis.
With Aizen's cooperation, Renya entered Muken alone and retrieved the second Hōgyoku.
As he gazed at the crystal-clear sphere in his hand, Renya knew
He had succeeded.
Aizen had never been his greatest concern. After all, in the original course of history, no one had truly died because of Aizen.
What Renya feared was what came next.
The Quincy invasion.
Too many would die in the war that followed.
Yamamoto Genryūsai, Sasakibe Chōjirō, Unohana Retsu, Ukitake Jūshirō…
And countless ordinary Shinigami whose names history would never remember.
Renya had no choice.
He had to kill Yhwach.
He had to destroy the Wandenreich.
And so, he prepared.
Obtaining the Hōgyoku was merely the first step.
After securing it, Renya left Seireitei and passed through the Senkaimon, arriving in the World of the Living.
Not long after, he stopped in a remote area.
A familiar presence emerged beside him.
"…Sister Suì-Fēng."
Renya spoke softly.
Suì-Fēng looked at him calmly. "Did you get it?"
Renya produced the Hōgyoku.
"I did."
Before Aizen's invasion, Renya had already revealed part of his plan to her. He told her he had discovered Quincy hidden within shadows, remnants of a power that had survived since ancient times.
He had entered the shadows to investigate and encountered an enemy beyond his current strength.
To survive, he needed the Hōgyoku.
Suì-Fēng approved.
Despite being the Commander of the Onmitsukidō and unwaveringly loyal to Soul Society, she was not someone who would sever personal bonds without hesitation.
Just as she once resented Yoruichi for leaving her behind
For the person she loved, she was willing to do anything.
"Are you sure you don't want me to go with you?" Suì-Fēng asked quietly.
Renya took out a modified spiritual device, inserted earphones, and handed them to her.
She listened.
"Sister Suì-Fēng," Renya's recorded voice said, "I need you to strengthen security especially around the First Division headquarters. The moment the Quincy appear, you must be able to respond immediately."
"The Quincy who kills Vice-Captain Sasakibe is named Driscoll Berci. His Schrift is 'O' The Overkill.' By killing others, he amplifies his own strength. The stronger the opponent he kills, the stronger he becomes."
"In recorded history, after killing Sasakibe and several Shinigami, he defeated Hisagi Shūhei before being incinerated by Captain-Commander Yamamoto."
"At the moment he appears, he will not yet be captain-class."
"You can kill him easily."
"And once he dies, we can analyze his Schrift in advance this will allow us to develop countermeasures against Sternritter abilities."
Suì-Fēng nodded. "I understand."
Renya stepped closer and embraced her, activating the second recording.
"Also, be careful. The Quincy can observe through shadows. Avoid any direct communication. The Wandenreich has spent centuries studying Shinigami abilities and devising methods to counter Bankai."
"Their main base exists within the shadow of Seireitei. Their observation of the Human World is weaker but still dangerous."
Suì-Fēng nodded again.
The third recording played.
"After I leave, Sister Suì-Fēng… you must publicly report my defection. Sever ties with me completely."
Her eyes darkened. "Do I really have to do this?"
Renya smiled. "Yes. It's the only way."
"…Understood."
Renya put the device away.
Though stripped of its communication functions, the tool retained extensive storage. Within it were countless recordings and images of Suì-Fēng.
For the next two years
Those would be what sustained him.
Renya took her hand. "I'm leaving."
She remained silent, reluctance etched into her face. They would not meet again for at least two years.
Renya leaned down, pressed a light kiss to her lips, then raised his hand.
A black Garganta slowly opened.
He stepped inside, waved once more
And vanished.
After Renya departed, Suì-Fēng returned to Seireitei at full speed.
She burst into the First Division headquarters.
"Captain-Commander," she shouted, "Kurotsuki Renya has defected!"
Yamamoto's eyes widened. "Defected?"
Suì-Fēng spoke rapidly. "He colluded with Aizen Sōsuke to steal the Hōgyoku. He tried to take me with him
I refused. He has fled to Hueco Mundo alone."
Yamamoto's expression darkened.
"Explain everything."