"Muten?" Ashido had already braced himself for sacrifice, only for the enemies before him to be wiped out in an instant. Shocked, his gaze fell on the uniquely shaped Myōki, and only then did he realize who had come. "It's... been a long time. And Rukia... you came back?"
"It's complicated," Rukia Kuchiki said, looking at the dense swarm of lower-tier Menos Gillian around them. "We'll explain later. For now, let's deal with these Hollows."
"Don't let the fight drag on, or more and more Hollows will be drawn here." Ashido fixed his eyes on the Long-Tailed Menos perched on the tree trunk, and on Aaroniero, the 9th Espada, beside him. "Take them out first. The Gillian will lose their commanders."
"Take us out?" The Long-Tailed Menos's newly shortened tail swayed behind him. "You're underestimating Aaroniero-sama far too much. This lord could kill even me with ease. Ugh!"
The Long-Tailed Menos's eyes widened. Behind the mask, his gaze crossed inward and saw the long blade piercing straight through his brow. "Aaroniero... sama?"
"You're right." "I can indeed kill you with ease." The two voices behind the long mask gradually merged into one. "We no longer need you."
That voice...
Muten Natsu stared at Aaroniero, his eyes trembling. "Who exactly are you? Why would you..."
"Why would I kill him?" Aaroniero swung his blade and destroyed the Long-Tailed Menos. The weapon in his hand was unmistakably a Zanpakutō. "Or why do I have this voice?"
"That voice is..." Rukia Kuchiki's eyes widened. "Ka... Kaien-sama!?"
That voice unmistakably belonged to Kaien Shiba, the man who had once looked after Rukia Kuchiki and Muten Natsu so kindly.
But why...
"Long time no see, Muten, Rukia." Aaroniero leaped down from the tree trunk and reached up to remove his mask. "Yo!"
Beneath the mask was a face that closely resembled Ichigo Kurosaki's, with short black hair, deep smoky-blue eyes, and the same distinctive long lower lashes as Ganju Shiba.
There was no doubt about it. This was Kaien Shiba's face.
But...
Muten Natsu took a step forward, then hesitantly drew half a step back.
Kaien Shiba... had already been killed by him.
He should have been dead.
"You two have changed so much. I almost didn't dare recognize you." A sunny smile appeared on Aaroniero's face. "You've both grown up..." His gaze paused briefly on Orihime Inoue. "And your kid's already this big?!"
"N-No... that's not..." Orihime Inoue turned bright red and hurriedly waved her hands. "I..." She had no idea what was going on.
Rukia Kuchiki lowered her voice. "He seems real."
"Very close." Myōki shifted slightly in Muten Natsu's hand as he activated Soul Essence Stealing, absorbing the Reishi leaking from the other party to speed up the analysis. "The feel of his Reishi is also..."
"What are you doing? What's with those looks?" Aaroniero pointed his thumb at himself and complained, "Everyone's favorite Lieutenant Kaien is still alive. Aren't you happy?"
Rukia Kuchiki and Muten Natsu stared at him blankly.
"...Don't just stand there in silence! At least snap back at me a little!" Aaroniero's arms drooped in disappointment. "You're making me feel like nobody likes me."
Ashido looked from one side to the other. "You know each other?"
"Of course! What did you think I've been talking about this whole time..." Aaroniero paused. "Well, this does make it hard to talk. Hey! You lot, go play somewhere else!"
Aaroniero waved a hand, and the surrounding Gillian answered with long, drawn-out cries before swaying off into the darkness.
Completely unguarded, Aaroniero sat cross-legged on the ground and tugged unhappily at his white robe. "Tch, Aizen's taste really is... Muten, you should be done analyzing me by now, right?"
Muten Natsu stared at the floating light screen in front of him. The Reishi analysis showed that the person before him was indeed Kaien Shiba. "Are you really Kaien-aniki? But..."
"I was already killed by you. And thank you for letting me face him alone." Aaroniero smiled, as if he had finally made peace with it. "I'm sorry I left you to face all of this by yourself... These past years must have been hard on you."
"Kaien-aniki..."
"I don't even have to think to know it. You've been blaming yourself all this time, haven't you?" Aaroniero stared sternly at Muten Natsu. "Ah, it's all my fault, I was wrong, if only I had done this or that. You just kept blaming yourself, trying to take everything onto your own shoulders..."
"I!" Muten Natsu's voice was dry. "I haven't..."
"Shut up!" Aaroniero pointed at Rukia Kuchiki. "Rukia, you tell him!"
"He has!" Rukia Kuchiki shot Muten Natsu a look. "Far too much."
Muten Natsu: "..."
"You stupid kid..." Aaroniero smiled helplessly. "If you want to become a proper adult, then before blaming yourself, you need to learn how to forgive yourself. You have to look forward, Muten."
"...Mm." Muten Natsu nodded softly.
That was right.
The Reishi, the Reiatsu, the way he spoke, and that warmth...
"It looks like you finally believe me." Kaien Shiba let out a long breath. "I was always worried you were torturing yourself too much, and I wanted to see you sooner. But for something more important, I had to stay here. Now I can tell you this clearly. You didn't do anything wrong back then. Because of your choice, we were given a chance to save the world!"
Rukia Kuchiki pressed him, "What exactly happened back then?"
"That night, not long after the battle, my collapsing soul shattered completely and came straight to Hueco Mundo," Kaien Shiba explained. "That Hollow, Metastacia, was one of Sōsuke Aizen's experimental subjects. Once destroyed, it would fly to Hueco Mundo and reassemble itself. After I reassembled with that Hollow, which had the ability to fuse with Spirit Bodies, I became what you see now. Up to that point, everything was still within their calculations. But they overlooked one thing. Do you remember Spiritual Class?"
Rukia Kuchiki nodded. Spiritual Class had once been a measurement standard used among the nobles, referring to the concentration of Reiatsu contained within Reishi.
Reishi contained Reiryoku, like water.
Plain water had limited destructive power, but once pressurized, it could cut through steel.
Raw Spiritual Power comes from the body-soul, but by compressing it and giving it conscious will, it becomes Spiritual Pressure that can be controlled and used as a weapon.
The concentration of Reiatsu that Reishi could contain was Spiritual Class.
Reiryoku was the innate gift of the body-soul. Reiatsu was the ability of the mind-soul. Spiritual Class was the talent of the Konpaku.
Ordinary seated members were divided into twenty ranks of Spiritual Class. Lieutenants fell between fifth and third rank, while anyone above third rank was Captain level.
When Kaien Shiba entered the Shin'ō Academy, his Spiritual Class had already reached sixth rank. He completed the six-year curriculum in two years and entered the Thirteenth Division as a 3rd Seat. Less than five years after that, he became Lieutenant of the Thirteenth Division.
If he had not always felt that he lacked seniority and believed many others deserved promotion to the Captain class more than he did, it would have taken even less time.
"If you remember that, I don't need to explain much." Kaien Shiba smiled smugly. "Simply put, my Spiritual Class was already close to third rank back then. Because my willpower was like steel, far beyond anything they imagined, the one who ultimately took control of this Spirit Body wasn't that Hollow. It was me!"
"R-Really?" Rukia Kuchiki asked, delighted.
"Of course! There were some difficulties along the way, but nothing I couldn't handle!" Kaien Shiba lifted his chin, put his hands on his hips, and laughed twice. "In short, that's how I took back my body, replaced the 9th Espada, and looked for a chance to get rid of Aizen... But Aizen's strength was even greater than I expected. Forget Aizen. Even the other Espada are hard for me to defeat."
"The Espada..." Orihime Inoue turned to look at Muten Natsu. "I think Muten defeated one."
"I heard. The 10th Espada, Yammy, right? His ability is special. After Resurrección, he needs a considerable amount of time to bring out his true strength." Kaien Shiba praised him, "Muten, your strategy was excellent. Defeating him before he fully released his power was the best approach. But that doesn't mean you can get careless. Resurrección is the Arrancar's ultimate power, but it isn't the Espada's final..."
The air suddenly trembled. The massive quartz trees around them shook, sending white sand and broken branches cascading down.
"Is it starting already?" Kaien Shiba glanced up at the darkness above at an angle. "No time to waste. It's already begun over there!"
"Over there?" Muten Natsu also looked up.
"In the direction of Las Noches. Aizen's plan has already begun. Everything you've done was within Aizen's plan, or rather... part of it." Kaien Shiba's expression turned grave. "Here it comes!"
["Can you hear me... intruders?"]
A tremor of Reiatsu echoed throughout Hueco Mundo, and everyone heard Sōsuke Aizen's voice at the same time.
"It's Tenteikūra!" Isane Kotetsu sensed the change in Reiatsu and turned to tell Yachiru Kusajishi.
Pfft!
Blood sprayed as Kenpachi Zaraki cleaved an Arrancar in two. Amid the scattering blood, Kenpachi turned his head. "Huh?"
"It's Glasses! Well, he doesn't have glasses now~" Yachiru Kusajishi reminded him. "Ken-chan, Baddie Ai-chan is talking to us."
"Is he going to tell me... where he is?" Kenpachi Zaraki rested his Zanpakutō on his shoulder. Crimson drops slid from the blade's tip, rolling into spheres in the air and reflecting the severed limbs scattered around him. "I was just getting annoyed that these guys weren't fun to cut."
On the way to Las Noches, large numbers of Hollows and Arrancar had been drawn in by Kenpachi Zaraki's unchecked Reiatsu, only to die beneath his blade.
Isane Kotetsu could not help worrying.
They had run into this many enemies along the way. Captain Unohana's side was probably facing the same thing.
But unlike Kenpachi Zaraki, Captain Unohana specialized more in healing.
Most importantly...
Isane Kotetsu looked at the sharply curved Zanpakutō hanging from her shoulder.
Most of the time, Retsu Unohana entrusted her Zanpakutō to Isane to carry.
When they had been attacked inside Garganta earlier, Isane had not had time to return the Zanpakutō to Retsu Unohana.
"What do I do..." Isane Kotetsu tightened her grip on the hilt of Retsu Unohana's Zanpakutō. "Captain isn't good at fighting, and her Zanpakutō is still with me. If she runs into enemies..."
Kenpachi Zaraki glanced at Isane Kotetsu and snorted.
["Allow me to express my personal respect to everyone who has invaded Hueco Mundo. Next, we... will begin our attack on the World of the Living."]
"The... World of the Living?!" Ichigo Kurosaki immediately thought of his family there. "They're going to the World of the Living?"
"Don't panic!" Renji Abarai said in a low voice, calming him. "This is exactly why not all the Captains came here."
["The repeated protection of Negación and the growth of the Arrancar's strength finally convinced Soul Society to invade Hueco Mundo. That also allowed me to successfully trap four Captains... inside Hueco Mundo."]
Nemu Kurotsuchi adjusted the equipment, then looked up and reported to Mayuri Kurotsuchi, "The original Garganta structure has been destroyed. Garganta cannot be constructed again in the short term."
"The data on hand is only enough to stabilize Garganta..." Mayuri Kurotsuchi wore a look of disgust. "Because Kisuke Urahara opened Garganta, I focused my research on stabilizing it. I never thought he would be this useless, ne."
["The greatest strength of the Gotei 13 is that each of its thirteen Captains can serve as a main combat force. But now, three have betrayed them, and four have been sealed away. One could say Soul Society's combat strength has fallen considerably."]
Inside Las Noches, a rift opened in the space before Sōsuke Aizen, revealing the clear sky over Karakura Town. With the aid of Kaname Tōsen's Tenteikūra, every word he spoke reached everyone's ears clearly. "From the information I deliberately left behind, you should have already predicted that I intend to open the Gates of Hell by destroying a large number of Souls. But just as I expected, you overlooked something... Hollows are Souls too. The Gates of Hell have already begun to open."
Behind him, the pitch-black Hōgyoku extended twisted tendrils, sketching the outline of a massive gate in the air. Two enormous, connected white skeletons could faintly be seen upon it.
"If you wish to stop me, come to Las Noches." Sōsuke Aizen stepped into Garganta. "As for me, I will destroy Karakura Town, create the Ōken, conquer Soul Society, and ascend to... the Soul King Palace!"
"This is Aizen's true plan!" In the Forest of Menos, Kaien Shiba explained further, "The Ōken is the key of the royal family. Do you still remember the Soul King?"
Shin'ō Academy had related courses on it. The Soul King was the king of Soul Society, and his palace existed in another space within Soul Society, guarded by royal agents.