Yama-jii's carelessness and arrogance have existed since ancient times... In the original timeline, he ignored the report submitted by Isshin Shiba that 'the emergence of Modified Menos Grande in the World of the Living has led to his failure to prevent Aizen's betrayal.'
Later, when Mayuri Kurotsuchi's Bankai was Mayuri Kurotsuchi by Uryū's arrow, he suggested that they prepare for the Quincy, but Yama-jii still ignored him.
And now, here, he confidently turned around, and Zero was instantly reborn!
The Soul Reaper, located in various corners of the Seireitei, all saw the two Negación. Ika recognized her brother among them and ran over quickly.
She was too far from Zero's side; even if she wanted to tell Zero to put his brother down, she couldn't. She could only watch helplessly as Seigen left from the Ninth Division, feeling deeply desolate...
Aizen, who was watching from the shadows, had not expected things to develop to this point. Nangong Ling's decisive rebellion seemed to have been premeditated.
Aizen was also shocked by the power of Yama-jii and Zero, comparing them in terms of Kidō, Bankai, and Reiatsu. Aizen judged that if he were to engage in a direct battle with either of them, he would definitely be no match for them.
'He should have control of the main forces over there. There must be plenty of Hollows that can be used as experimental subjects. I need to find an opportunity to go there...'
Aizen deduced that Zero had been taken away by Hueco Mundo, which Aizen found quite intriguing.
Aizen was unaware that Zero, after being ambushed, had already noticed his machinations and was planning to create a large number of Spirit Worm to monitor Soul Society after returning to Hueco Mundo.
Because of Zero's rebellion, thousands of people died violently in the Seireitei, most of them nobles, and very few were Soul Reaper).
The important Captain-level survived; the most powerful among the dead was the leader responsible for guarding Central 46, followed by Tokinada Tsunayashiro.
Most of the victims were caught in the blast of Ryūjin Jakka Yama-jii -no-Kage, and were later covered by 'Five Dragon Destruction'.
The somber mood of the Gotei 13 didn't last long, after all, it was the detestable Central 46 who had died... The reconstruction of Central 46 was swift; twenty sages were gathered in just one month, and it would be fully reorganized in another two months...
Three months later, Hirako succeeded Aizen as the Fifth Division Captain Gotei 13. He promoted Aizen to Vice-Captain in order to keep an eye on him, because Aizen gave Hirako a vague sense of danger.
Aizen also demonstrated remarkable work ability, managing everything meticulously. Among the recent graduates of the Shin'ō Spiritual Arts Academy, he recruited several promising talents, such as an inspiring young man named Kaname Tōsen...
On the 11th Division side, Kiganjō has also been promoted to the tenth generation Kenpachi... At this moment, the Captains are very relieved because this big oaf looks like he has muscles but doesn't have the overwhelming power of Nangong Ling.
Compared to the jubilant Kiganjō, Vice-Captain Ashido was clearly in low spirits. He had racked his brains trying to figure out why Zero would collude with the enemy, who was, after all.
The Menos Grande of the Arrancar Army did not reject the arrival of Maki and the others; some even licked their lips, revealing a drooling expression, before restraining themselves after being warned by Zero.
Since returning to Hueco Mundo, Zero first had the Scientific Hollows create a large group of Hollows no bigger than flies to monitor parts of Soul Society and Seireitei, with specialized Hollows taking turns in charge.
The reason why we can only monitor certain parts is because these phantoms are too small, and their Reiryoku is naturally weak. Even if they are only within a hundred meters of Captain-level being, they will be crushed by Reiatsu.
Even getting within ten meters of Fifth Seat captain would result in death, mainly because they are too weak... The Scientific Hollows are also actively researching and hoping that they can get within ten meters of Captain-level.
As per Zero's instructions, all the Squad within the Seireitei were deployed, especially the Fifth Division, which was originally under the control of Seigen, with dozens of units hidden within it...
After setting up the surveillance Spirit Worm to find the mastermind, Zero was completely immersed in analyzing the Hollowfication of the Seigen. Currently, there are already Menos Grande that can be 'Half-Arrancar' here, but unfortunately, there are only two of them.
If Zero can solve the problems with the Seigen, and through reverse reasoning experiments, perhaps the research topic of 'Complete Arrancarization of Intermediate Menos Grande' can also make great progress.
Just as he was engrossed in his research, a Hollow reported that the outlying region was under attack by a different Menos Grande Hostile Faction, suspected to be the Baraggan forces... Zero immediately summoned his forces and ordered them to investigate the enemy forces.
In the Menos Grande Forest at the outer edge of the Hueco Mundo Circle.
As the leader of the vanguard, Yaxiao searched for traces of the enemy legion and finally led his troops in pursuit after spotting two Adjuchas.
The leader, Yaxiao, had considered the possibility of a trap, but his recent improvement in abilities made him completely fearless...
Upon closer inspection, Yaxiao's current form is that of a four-meter-tall upright giant, no longer the toad-like figure he once was... The mask only covers his mouth and above, making him a Half-Arrancar Adjuchas.
During the pursuit, several Cero appeared out of nowhere, instantly killing two Adjuchas in the pursuing force. Sure enough, the ambush appeared, with more than a dozen Adjuchas surrounding the Yaxiao's forces.
"Hmph, only one lackey came? What a pity!"
An elderly humanoid figure appeared, his body slightly bloated. He wore a gray robe and spoke with utter contempt for Yaxiao.
"You are... Baraggan?"
Yaxiao looked up at this human-like figure. The voice was unchanged, but the Reiatsu was slightly strange. However, Yaxiao could sense that it was the same Arrancar Reiatsu as Ulquiorra and Starrk.
"How dare you! How can you address the Great Emperor by his name so casually?"
"Go to hell!"
Two henchmen angrily rebuked Yaxiao and attacked with incredible speed. Yaxiao's large mouth, no longer covered by a mask, twisted into a cold smile.
First, a Lion-Headed Lesser Hollow with Reiatsu of 1.1 chariots scratched at the belly of the Yaxiao with its claws, but the Yaxiao's belly didn't even have a scratch.
The other upright lizard was no weakling either, possessing Reiatsu of 0.9 chariots. It lashed out with its tail at Yaxiao's neck...
Yaxiao casually caught the lizard's tail and sneered, "Heh, you think you can break through my Compressed Hierro Defense with this little skill? Die!"
"Ah!"
A burst of Reiatsu condensed in Yaxiao's right hand into a blade emitting a yellow light, which he used to kill the lizard.
"What?"
Lion Head tried to dodge, but Yaxiao caught up and easily killed him with another slash.
"Hmm? That powerful? It looks like Arrancar, but its Reiatsu isn't even close to Arrancar's level. Could it be Modified Type? Hmph, I'll capture it first..."
Baraggan saw Yaxiao easily kill his two Guards, his expression turned strange, and he took matters into his own hands.
Yaxiao sensed something was wrong and turned to run, but he was no match for Baraggan. In just two exchanges, he was sent flying by a palm strike, crashing through several Quartz Trees before finally coming to a stop.
On the other side, Yaxiao's subordinates were slaughtered amidst screams; compared to the elite troops brought by Baraggan, those guys were too weak.
"Negación!"
Yaxiao raised his right hand and summoned the Negación attack from the distant Las Noches. He was about to escape, but a sensation that Spatial Distortion came over him, and the Negación was forcibly deflected to another direction.
"Hehe, with me here, your Negación is malfunctioning."
A creature with an antenna on its head laughed loudly. Its ability was to disrupt and distort space, preventing nearby enemies from Sonído and accurately releasing Negación protection to protect their teammates.
"You bastard!"
Yaxiao also possessed similar spatial abilities, cursed angrily, "This time I'm really doomed, I didn't swallow any experts."
"Boy, I remember you. How did you become like this? Confess honestly, and I'll allow you to surrender."
Baraggan was curious about Yaxiao's demeanor. This guy clearly only had 1.8 car's worth of Reiatsu, but his combat power was like Vasto Lorde's, easily capable of annihilating his two subordinates.
"Look at you like this? Haha, our legion will soon be all Arrancar. You're the one who should surrender, Baraggan..."
Yaxiao also had backbone. He suddenly charged towards Baraggan, his hand still gathering Cero... Yaxiao wasn't stupid. If he surrendered, he would be dissected and studied by that lunatic Szayelaporro. He might as well die and let them study him. It would be less painful.
Indeed, after Baraggan killed the Yaxiao, he gave its body to Szayelaporro, asking him to investigate the feasibility of this Half-Arrancar.
"Yaxiao is dead? Baraggan Arrancar?"
Zero frowned. Yaxiao was considered one of the higher-ups, and he was the first to become Half-Arrancar. Their side suffered heavy losses.
"Hmm! The inspector said the Negación couldn't save him; it was Negación open..."
Ulquiorra's tone was indifferent, but his eyes revealed a hint of surprise. He sensed that Zero's emotions were running high, seemingly out of anger.
He felt he had learned something new: that he should be angry when his comrade died.
"Dispatch a large number of Spirit Worm to monitor the surrounding area and locate them. Have all our Adjuchas scattered in the outer circle return to the inner circle. Once the experimental data stabilizes, everyone prepare to receive the 'Half-Arrancarization' amplification..."
Zero directly ordered the entire army to break through. Over the years, they had plundered several thousand souls with Reiryoku in the Soul Society, and dozens of Soul Reaper as well.
The Reiryoku of those souls was forcibly extracted and then injected into Adjuchas's body for experiments... The souls whose Reiryoku was extracted could only be reincarnated as Reishi.
It's not possible to make Adjuchas fully Arrancar and possess Zanpakuto yet, but it's still possible to improve them in all aspects and double their combat power, just like Yaxiao.
Twenty Adjuchas are currently undergoing Arrancar experiments in the Laboratory, and it should be completed soon...
Two months later, twenty Half-Arrancar Adjuchas appeared, 14 of which had completed their upgrades, with their speed, attack power, defense, and even their own abilities all increasing by about 100%.
Six failed evolutionaries, their masks also resembling Half-Arrancar masks, but their minds have become abnormal, and their movements are very Slowing. These failed Half-Arrancar masks seem to have degenerated from Adjuchas into Gillian...
A 70% success rate is extremely tempting, and most Adjuchas, whose evolution has almost ceased, choose to take the gamble...
Some Adjuchas with a base Reiatsu of Three Carriages can increase their Reiatsu to 2 after transformation, and with the improvement in various abilities, they can completely challenge Vasto Lorde. (For example, Hammerhead Shark defeated Tier Harribel.)