Thump!
A dull sound rang out. Upon hearing Toshiro agree to fight him beyond the heavens of Las Noches, Aizen stomped his right foot on the ground, and his entire body shot upwards like an arrow leaving the bowstring.
Seeing this, Toshiro did not hesitate. He also kicked off the ground and shot into the sky.
Whoosh!
Whoosh!
In just an instant, Toshiro and Aizen flew to the 'ceiling' of Las Noches. If they didn't stop, it seemed they would crash into the 'ceiling'.
Just then, while still flying upwards, Aizen casually swung his sword, blasting a large hole in the 'ceiling' of Las Noches, and his body shot out through the blasted hole.
Toshiro followed closely behind, rushing out through the hole.
Whoosh!
As their vision darkened, Toshiro and Aizen arrived 'beyond the heavens' of Las Noches.
"So this is... above the heavens of Las Noches?" Toshiro stood on a huge stone pillar on the roof of Las Noches, surveying the surrounding scene.
Huge stone pillars pierced through the roof of Las Noches, reaching towards the sky like pillars holding up the heavens, supporting the entire Las Noches.
A crescent moon hung alone in the sky, brightening the otherwise dark night somewhat.
Unlike the blue sky and white clouds inside Las Noches, the area beyond the heavens of Las Noches was the same as the scenery of Hueco Mundo, both in the middle of the night.
"Yes, this is indeed beyond the heavens of Las Noches." Aizen's voice came from not too far opposite Toshiro.
Toshiro looked over and saw Aizen standing on a 'heavenly pillar' not far opposite him. And from Toshiro's angle, the crescent moon in the sky seemed to hang behind Aizen, adding a solemn and sacred halo to him.
Aizen looked at Toshiro and spoke quietly: "Hitsugaya-kun, you know? There are two forbidden things beneath the heavens of Las Noches."
"First is the Cero that exists only for the Espada… [Gran Rey Cero]. Second is the release of Espada number four and above."
"The space of Las Noches cannot withstand either the Gran Rey Cero or the release of Espada number four and above. That is why I invited you, Hitsugaya-kun, to fight beyond the heavens of Las Noches."
"Alright, Aizen, I'm not interested in listening to your nonsense. We are directly above Las Noches. If we start fighting, it will also affect the inside of Las Noches. So, let's move farther away from Las Noches!" Toshiro said expressionlessly.
Having said that, Toshiro chose a random direction, flickered, and stepped into the air, disappearing.
Aizen's eyes flashed with a strange light. After hesitating for a moment, he also turned and followed.
In fact, the reason Toshiro chose another location far from Las Noches, rather than fighting above the heavens of Las Noches, was not only because he was worried that the aftermath of the battle would affect Rangiku, Nel, and the others inside Las Noches, as well as the Shinigami of the Hueco Mundo expeditionary force, but also mainly because he was concerned about any conspiracy Aizen might have.
Aizen would stop at nothing to achieve his goals. It was possible he had set traps or snares to deal with Toshiro. So, to be on the safe side, Toshiro still did not fight at the location chosen by Aizen.
Whoosh!
In just a moment, on a hillside one hundred kilometers away from Las Noches, the figures of Toshiro and Aizen stopped, one after the other.
"Right here, Aizen!" Toshiro said in a deep voice.
"Fine. I don't mind. It's the same anywhere." Aizen said, seemingly unconcerned.
"Then let's begin the fight!" Toshiro said in a deep voice.
Having said that, Toshiro pointed his sword to the sky and chanted softly: "Bankai! Daiguren Hyorinmaru!!"
Boom!!!
A vast Reiatsu, as vast as an ocean, burst forth from Toshiro's body. In an instant, it seemed the entire space of Hueco Mundo trembled.
Boom!
Boom!
Boom!
Pillars of blue Reiatsu shot into the sky. Then, dark clouds gathered in the sky, making the night, which was somewhat bright under the crescent moon's illumination, even darker.
Rumble—!!!
Thunder and lightning flashed within the dark clouds, serpents of lightning rolled about, as if divine punishment was descending upon the world.
Crack, crack, crack...
Freezing cold air emanated from Toshiro's body. Wherever the cold air passed, everything was frozen. Looking around, within dozens of kilometers, the land originally composed of sand and dust, lacking moisture, had all turned into a world of ice and snow.
At the same time, Toshiro's body began to grow rapidly. His original height of 1.33 meters increased to 1.8 meters. His youthful, elementary-school-student-like face transformed into that of a handsome, dashing young man. Then, a set of armor formed of ice crystals covered the vital parts of Toshiro's body.
"Yare yare, Hitsugaya-kun, are you trying to kill me right from the start?" Seeing Toshiro's earth-shattering Bankai scene, Aizen didn't show the slightest sign of being moved, instead teasing with a smile.
"Of course. Otherwise, I wouldn't have the free time to come all the way to Hueco Mundo for a spar with you." Toshiro said in a deep voice.
Having said that, looking at Aizen's composed, calm, and leisurely manner, Toshiro couldn't help frowning.
Everything within dozens of kilometers of Toshiro was frozen. And this was even though Toshiro deliberately restrained his Reiatsu for fear of affecting his companions inside Las Noches. Otherwise, he could freeze even a range of hundreds of kilometers. After unleashing his full Bankai, Toshiro was this powerful.
And although the frozen range was now reduced, the power of the ice-cold air in the surrounding space was even stronger.
However, it could only be said that Aizen is truly Aizen. Even though Toshiro unleashed such momentum, Aizen remained unmoved. Even within the core range affected by Toshiro's Reiatsu, even with everything around him frozen, he remained transcendent, as if unaffected.
"It seems Hitsugaya-kun is determined to kill me. Well, there's no choice then. To show my respect for Hitsugaya-kun, I will also fight with all my strength!" Aizen put away his smile and said in a deep voice.
Having said that, Aizen also unleashed his full Reiatsu without reservation.
Boom!!!
A vast, powerful Reiatsu burst forth from Aizen's body, no weaker than Toshiro's.
'This Reiatsu... It seems after obtaining the complete Hogyoku, Aizen's strength has indeed increased considerably.' Toshiro thought to himself.
Previously, when Aizen betrayed Soul Society, Toshiro had fought him. At that time, although Aizen was indeed on the same level as Toshiro and Yamamoto, his Reiatsu was somewhat weaker than Toshiro's, let alone compared to Yamamoto.
Later, even after forcibly fusing with the Hogyoku during the fight, Aizen's Reiatsu was only a notch stronger than Toshiro's. Yet, even then, his combat power was roughly on par with Toshiro's, and he might even have been suppressed by Toshiro.
But now, even without using the Hogyoku, Aizen's Reiatsu could match Toshiro's. And this was even considering that Toshiro had also made considerable progress in strength during this time.
Crack, crack, crack...
While Toshiro was surprised by Aizen's strength, everything frozen within dozens of kilometers began to show cracks under Aizen's Reiatsu, as if it might shatter Toshiro's ice at any moment.
"Hmph!" Toshiro snorted coldly, directly mobilizing his Reiatsu to blast towards Aizen.
Boom!!!
An earth-shattering explosion sounded. At the moment Toshiro and Aizen's Reiatsu collided, the entire world seemed to fall silent. Then, the entire space of Hueco Mundo was torn apart. Pitch-black fissures appeared in the void, and black serpents of lightning danced wildly within the cracks.