Within the domain.
"Boom!"
A loud bang suddenly exploded.
Aizen's slender fingers gently waved, and a beam of white lightning instantly shot out from his fingertips.
Even Hado Number Four, under the spiritual pressure of a Shinigami at his peak, possessed astonishing power.
The lightning was like a giant white lightning dragon, roaring as it rushed into the distance, its might surprisingly akin to a Cero.
The chain trembled violently, as if struck by a heavy hammer.
However, it quickly returned to calm.
Aizen slightly narrowed his eyes; before he could discern the effects and abilities of this domain from the traces, two ghost-like black slashes flew towards him.
The slashes were extremely fast, arriving in an instant, and the black flames entwined on both sides of the blade seemed like demonic flames from Hell, as if they could devour everything, causing Aizen's heart to leap.
—Extremely dangerous.
He quickly made a judgment in his mind.
Immediately after, Aizen's figure flickered, using Shunpo to instantly disappear from his original spot.
"Bang!" A barely perceptible crack appeared on the ground.
Aizen keenly caught it while moving, and then a thought flashed through his mind like a spark.
Before he could sort out this sudden idea, a series of slashes came at him one after another.
Yoriichi's every strike was precisely aimed at Aizen's weaknesses.
Perhaps in the eyes of others, Aizen was flawless; both his skill and technique were at the pinnacle of a Shinigami.
But under the observation of Touhou Sekigan, every subtle flaw was exposed.
Muscle contraction, reishi release, and visual observation...
Aizen's actions of seeing an attack and then evading it were not simultaneous.
The slight delay in between was where his weakness lay.
"Whoosh!"
A whooshing sound of wind, as the blade cut across Aizen's body, instantly echoed in this quiet, deathly still space.
Although Aizen evaded in time, his movements were always a beat slower than his thoughts.
He looked at the dark blood slowly flowing down his shoulder, a barely perceptible solemnity flashing in his eyes.
—The defense formed by the reishi gap was easily torn apart!?
He mused to himself.
He understood the principle of brute force, which was simply to forcefully break through an opponent's reishi with powerful musculature, thereby causing damage.
But that last hit...
"Can your Bankai ignore the reishi difference between us?" Aizen raised his eyes, his surprise growing.
The ability to ignore reishi was not rare; Tōsen Kaname's Bankai could also do it, but it was limited to situations where the difference was only one tier.
If the gap was too large, the Bankai could be easily torn apart.
But what about Tsugikuni Yoriichi?
The difference between the limit of a Shinigami and a second-tier is not just one level.
"..."
Yoriichi did not answer him, but this silent response was the best answer.
"Bang!"
Yoriichi disappeared from his spot again, moving forward with Shunpo.
Illusory flames wrapped around the ethereal blade.
Seeing this, Aizen regained his usual serious expression.
"A very peculiar ability," he said calmly.
A bolt of lightning wrapped around Kyōka Suigetsu, and he swung it towards Tsugikuni Yoriichi.
—Hado Number Eleven: Tsuzuri Raiden!
At the same time, he continued to shift his position, his voice leisurely sounding:
"You are strong; this is the first time I've praised a Shinigami."
"In a direct confrontation without releasing Zanpakuto, even Yamamoto Genryusai might not be your match."
After a period of intense combat, Aizen had already understood that reaching the pinnacle was not the ultimate point of all skills.
Above that, there was probably another stage, which was the indescribable realm of Tsugikuni Yoriichi.
It was likely the unity of heaven and man, where any illusion could be seen through, and any attack could be dismantled.
In terms of speed, he was already at the limit of a Shinigami.
He had not expected that Tsugikuni Yoriichi would be so close to him, and even, in terms of reaction, superior.
If not for that, he would not have been injured.
Aizen slowly exhaled, his vision reflecting the scene of himself using Hado to defend against the slashes.
He could feel something frantically corroding his flesh at the wound.
If nothing unexpected happened, this might be a substance related to Hell.
Considering Tsugikuni Yoriichi's Zanpakuto ability, once the corrosion reached a certain stage, Hell Gate would appear, delivering a fatal blow.
"A one-hit kill with a similar effect?" Fortunately, the medicine barely suppressed the corrosion; otherwise, Aizen would now be contemplating how to remove these substances.
Between breaking free from this space and being dragged into Hell by Hell Gate, the latter was undoubtedly more urgent.
"Whoosh..." A heavier breathing sound emerged.
Aizen extended his hand and instantly chanted: "Bakudo Number Twenty-One: Sekienton."
In an instant, red smoke burst forth from his original spot, enveloping Aizen's body.
"Whoosh!" Accompanied by a faint whooshing sound, Aizen flew away from the suppressed environment.
After the previous battle, he had calculated in his mind and had roughly understood the Bankai's ability.
If nothing unexpected happened, the surrounding chains were the medium for maintaining this Bankai; if he could destroy all of them at once, the Bankai would also disappear.
Unfortunately, there were too many chains; the white lightning impact could only make it resonate, unable to leave even a faint white mark.
Perhaps Hado Number Ninety-Nine could be effective, but that Hado required too much reishi.
His body was currently abnormal, so he couldn't take risks.
Furthermore, the chains could absorb his reishi and feed it back into the environment's restoration; the broken ground earlier was quickly restored.
Therefore, the more reishi he wasted here, the more advantageous it would be for Tsugikuni Yoriichi.
But he had to release reishi because Tsugikuni Yoriichi's defense-ignoring slashes could only be resolved with Hado...
Kyōka Suigetsu was directly shattered by a small half after colliding with that eerie black blade.
Considering everything, Aizen came to two conclusions.
Don't use Hado, die immediately; use Hado, live temporarily.
But he still couldn't escape the result of a slow death.
A very troublesome Bankai.
But fortunately, it was not without weaknesses.
Using Sekienton was to buy some time and, at the same time, seize an opportunity to act.
The moment the thought fell, Aizen had already flown away, the red smoke obscuring Yoriichi's vision, but not blocking the observation of Touhou Sekigan.
From some movements, it could be judged that something had happened to Aizen.
Yoriichi quietly watched him.
Then, the black sharp blade in his hand disappeared, and a black longbow, accompanied by the convergence of reishi, appeared in Yoriichi's hands.
He drew the bow, and an arrow condensed.
Charging.
"Creak..."
"Bang!" The smoke dispersed due to the strong wind.
Aizen had just heard the sound and hadn't had time to observe or dodge when, with a "whoosh," his chest was pierced, and a black sharp arrow reflected like the wind in Aizen's eyes.
His pupils slightly contracted, feeling the pain that followed closely.
Immediately after.
He barely managed to turn his body, a hint of surprise flashing in his eyes.
"Quincy?"