"Ha!"
After their Reiatsus collided inconclusively for a while, Toshiro ceased probing, let out a loud shout, and suddenly swung his sword, charging towards Aizen.
Bang!
Toshiro's speed was so fast that the air seemed to let out a popping sound as if overwhelmed. Then, Toshiro's figure appeared before Aizen in an instant, and he violently swung his sword down at Aizen's head.
Aizen reacted quickly, raising his sword to meet Toshiro's attack.
Clang!!!
Their Zanpakuto, coated with Reiatsu, clashed together, producing a huge metallic clanging sound.
Boom!!!
The powerful Reiatsu shockwave directly destroyed the surrounding objects that had been frozen by Toshiro's ice-cold power.
Toshiro and Aizen were both sent flying backwards by the recoil from the sword clash.
"Vacuum Ice Blade!"
While still in mid-air after being sent flying, Toshiro took the opportunity to launch a Shikai ability of Hyorinmaru.
Whoosh! Whoosh! Whoosh!
Hueco Mundo, which had always been a desolate desert landscape, seemed to suddenly experience a downpour. Hundreds, thousands, perhaps tens of thousands or hundreds of thousands of diamond-shaped ice blades rained down overwhelmingly on Aizen, who was also flying backwards.
With nowhere to dodge in mid-air, Aizen could only swing his sword to counter.
Whoosh! Whoosh! Whoosh!
In an instant, Aizen slashed out countless Kenatsus, slashing towards the sky full of ice blades.
Bang! Bang! Bang!
Each of Aizen's Kenatsu was like a huge stream of light, wiping blank traces across the sky covered by the diamond-shaped ice blades.
"Ryusenka!!"
While Aizen was frantically dealing with the sky full of ice blades, a flash of blue light appeared behind Toshiro. A pair of huge ice-frost wings appeared on Toshiro's back, halting his backward flight.
Then, Toshiro flapped his wings, and his figure instantly shot towards Aizen at an extremely fast speed.
On the other side, Aizen barely reacted just as Toshiro was about to get close. However, by then, Aizen had no time to dodge. At the critical moment, Aizen could only hold his Zanpakuto horizontally in front of himself.
Clang!
The tip of Toshiro's Zanpakuto pierced the blade of Aizen's Zanpakuto.
Crack, crack, crack!!!
The moment Toshiro's sword tip touched Aizen's Zanpakuto blade, Aizen, along with his sword, was instantly frozen into a cross-shaped block of ice.
Whoosh!
Toshiro flapped his wings and stopped his figure dozens of meters behind Aizen.
Crack, crack, crack… boom!!!
Just as Toshiro turned around, preparing to attack while Aizen was frozen in the cross-shaped ice, Aizen had already shattered Toshiro's cross-shaped ice block with his immensely powerful Reiatsu.
Whoosh!
However, just as Aizen broke free from the ice, Toshiro was already upon him again. Aizen could only passively defend once more.
Clang!
Swords clashed. After reacting, Aizen blocked Toshiro's attack again.
Creak—!!!
Their Zanpakuto pressed against each other, locked in a temporary stalemate. Then, as the blades ground against each other, sparks continuously flew out.
"Heh, I couldn't push you back even a single step. It seems not only your Reiatsu but even your physical strength has increased considerably, huh? Aizen." Toshiro said with a cold smile, looking at Aizen right before him, while increasing the force in his hand.
"How embarrassing. Although my strength has indeed increased quite a bit, it still seems insufficient to defeat you, Hitsugaya-kun!" Aizen said, forcing a smile while barely handling the increasingly powerful force from Toshiro's Zanpakuto.
"Ha!"
Seeing that he couldn't overcome Aizen for the moment, Toshiro suddenly let out a loud shout. The huge blue ice-frost wings on his back flapped violently, and a powerful propelling force came from the ice wings behind him, which Toshiro applied to his Zanpakuto.
Then, Aizen felt a powerful force suddenly transmitted from Toshiro's Zanpakuto, instantly breaking the stalemate. Aizen's feet scraped against the ground, and his body involuntarily slid backwards rapidly.
Seeing that the ice wings on his back were effective, Toshiro continued to flap his ice-frost wings repeatedly.
With the boost from the propelling force generated by the ice wings on his back, Toshiro's strength had surpassed Aizen's. Aizen's body was continuously pushed backwards by Toshiro, and even the frozen ground was scraped into a deep furrow by Aizen's feet.
Bang!
Bang!
Bang!
Aizen's body was pushed by Toshiro, crashing into one frozen boulder after another.
"..."
As boulder after boulder was smashed to pieces, no matter how tough Aizen's body was, it gradually couldn't hold on. Finally, Aizen couldn't help but spit out a mouthful of blood.
Then Aizen felt that if this continued, he would definitely be smashed to death...
Thinking this, Aizen let out a soft shout, then suddenly raised his right foot and stamped heavily on the ground.
Boom!
The ice-crystal-covered ground instantly collapsed. Aizen's body suddenly sank into the ground. Toshiro, because of the sudden ground collapse, lost his balance and staggered, and the force he was applying to Aizen's Zanpakuto momentarily loosened.
Whoosh!
Taking advantage of this opportunity, Aizen's figure flickered, instantly breaking free from Toshiro. Then his figure flickered repeatedly, putting a large distance between himself and Toshiro, and looked at Toshiro with a vigilant expression.
Whoosh!
Toshiro also flickered, jumping out of the collapsed ground, and then stood opposite Aizen across a distance.
"Yare yare, truly impressive, Hitsugaya-kun. I have to give you credit. Even with nearly identical Reiatsu, your combat ability is unquestionably above mine. You certainly live up to your reputation as the Strongest Ice-type Zanpakuto user." Aizen said, wiping the blood from the corner of his mouth.
Logically speaking, with similar Reiatsu, their combat abilities should also be very close. However, since the battle began, Aizen had been continuously suppressed by Toshiro, clearly showing that Toshiro's combat ability was still a notch above Aizen's.
In fact, this was mainly due to their Zanpakuto. Toshiro's Zanpakuto is the Strongest Ice-type Zanpakuto, with various powerful techniques. In terms of attack power, only Yamamoto's Ryujin Jakka can barely compare. Truth be told, Toshiro's Hyorinmaru could almost be called the strongest Zanpakuto.
And Aizen's Zanpakuto, Kyoka Suigetsu, can be said to be the Strongest Illusion-type Zanpakuto. Its ability of complete hypnosis is indeed overpowered.
However, an illusion type is still an illusion type. Although its abilities are strange and overpowered, when it comes to actual attack power, elemental-type Zanpakuto like Toshiro's ice type and Yamamoto's fire type are superior.
Not to mention anything else, just talking about Zanpakuto abilities, Toshiro's Hyorinmaru and Yamamoto's Ryujin Jakka inherently come with many immensely powerful attack skills.
However, aside from its hypnosis ability, Aizen's Kyoka Suigetsu itself has almost no offensive capabilities. So, every time Aizen fights, he either uses Kido or just attacks directly with his Zanpakuto using Reiatsu. He has never been seen using his Zanpakuto to perform any offensive skills other than hypnosis.