Inside the training space, an open area that had been separated out.
The space here was also accelerated, with one month inside equal to one day outside.
Ichigo gasped heavily, sweat soaking his Shihakusho, dripping from his chin onto the ground, instantly absorbed by the ground.
He supported himself on his knees, Zangetsu thrust diagonally beside him, his gaze towards the figure opposite filled with frustration and confusion.
Setsuna stood ten meters in front of him, completely at ease, not even a corner of his clothes wrinkled.
He had just used only the most basic Hakuda… simply the application of fists, feet, elbows, and knees.
Yet in Ichigo's eyes, this seemingly simple Hakuda was like an insurmountable chasm.
No matter how he urged his Reiatsu, how he swung Zangetsu, how he performed Getsuga Tensho, or even tried to use that Hollowfication power...
All his attacks were casually blocked by Setsuna, or even deflected by Setsuna using his own force, sending shockwaves back that made his own blood and energy surge.
What made him feel most powerless was that Setsuna didn't even use power exceeding Ichigo's own Reiatsu level. It was purely a crushing of skill and mastery.
Ichigo straightened up, wiped the sweat from his face, and his voice was full of self-reproach: "Senpai, I'm sorry. I'm just too weak."
His voice carried dejection.
How could someone like this challenge Yhwach, who had killed Captain-Commander Yamamoto? How could he extract his mother's soul from within him?
Setsuna shook his head slightly. "I misjudged. The direction of my instruction was off."
"Off?" Ichigo was confused. He felt that the senior had taught him very well.
"I overlooked the most basic factor… time." Setsuna said. "Compared to Shinigami Captains who have lived for hundreds of years and honed their skills in countless battles, you are far too young."
"The polishing of combat skills requires the accumulation of time and the tempering of a vast number of battles."
"To expect you to catch up to the skill level of those veteran Captains in just a few short months, to the point where you can contend with Yhwach, is indeed unrealistic."
"Then... what should I do?" Ichigo became even more bewildered.
"Since your skills aren't up to par, then go all in on 'numerical values'. Simply put, focus on enhancing the power of [Getsuga Tensho]." Setsuna's tone carried a hint of amusement.
Who doesn't know that Ichigo is a pure numerical monster? Although he knows some other moves, the decisive factor has always been Getsuga Tensho.
Ichigo's eyes lit up as expected. "Yeah, yeah, that's what I was thinking too."
Setsuna continued, "The battle of Shinigami is the battle of Reiatsu. This statement may not apply to some people, but it fits you perfectly."
"You just need to increase your Reiatsu as much as possible, and [Getsuga Tensho] will naturally become stronger."
"But how can I continue to increase my Reiatsu?" Ichigo frowned. His Reiatsu was naturally very strong, and he had almost never trained it.
Setsuna examined Ichigo. "Your talent is exceptional. You are almost a natural 1st-Class Reiryoku. In your battle with Aizen, you actually already reached the realm of the [Transcendent]."
"Transcendent?" Ichigo heard this term again.
"As the name implies, it means an existence that transcends the conventional limits of a Shinigami." Setsuna explained. "Upon reaching this level, your Reiatsu, life form, and the essence of your power will all undergo a qualitative leap."
Ichigo nodded slightly. He was indeed much stronger than ordinary Captains now.
Setsuna continued, "But merely being a Transcendent is not enough to defeat Yhwach. His true strength is at least at the level of a second-stage Transcendent."
Ichigo was dumbfounded. "You can transcend twice?"
Setsuna nodded. "For example, Captain-Commander Yamamoto and I. We tempered the power of our souls to the limit, thereby breaking the conventional upper limit of Reiatsu."
"You and Aizen, on the other hand, broke the boundary between Shinigami and Hollow, fusing the two opposing powers to obtain a higher-level power."
"When did I break..." Ichigo started to say, then suddenly realized. The [Hollowfication] he mastered was precisely breaking the boundary between Shinigami and Hollow.
In a sense, Aizen's Arrancar were similar, but those Arrancar were infused with Shinigami power on the basis of Hollows, and the two powers did not achieve balance.
Whereas his Shinigami and Hollow powers originated from the depths of his soul and were balanced.
"So, if I want to surpass my limits again, I need to transcend the essence of my soul like you and Captain-Commander Yamamoto?" Ichigo frowned. This seemed even harder than refining one's level, didn't it?
Otherwise, there wouldn't be only a handful of Transcendents in the long history of Soul Society.
Setsuna shook his head slightly. "There's no time for that. But you have a third way to transcend."
"A third?" Ichigo's eyes widened.
Setsuna nodded. "Just as Shinigami and Hollow are two sides of the same coin, Quincies and Fullbring are also two sides of the same coin."
Ichigo was shocked. "How are Fullbring and Quincies connected?"
Setsuna explained, "Yhwach calls himself the progenitor of the Quincies, but in reality, the true source of Quincy power is the Soul King."
"As for Fullbringers, the root of their power awakening is that during their mother's pregnancy, an extremely tiny fragment of the Soul King accidentally merged into their bodies."
"This fragment attracted the attack of a Hollow, and also endowed the offspring with the potential to manipulate the souls of matter."
Ichigo murmured to himself, "So that's how Fullbring came to be?"
Setsuna looked at Ichigo and said in a deep voice, "Combining Fullbring and Quincy power will only allow you to catch up to Yhwach. To kill him, you'll still fall short."
"Only by fusing these four opposing powers together, breaking all known boundaries, reaching an unprecedented height, and becoming an [Ultimate Transcendent] existence, can you truly kill Yhwach!"
After hearing this, Ichigo couldn't help but gasp.
He had been confused and achieved breaking the boundary between Shinigami and Hollow naturally.
Now, unifying four powers? Was that expecting too much of him?
Setsuna looked at the stunned Ichigo, his own mind calmly thinking.
He taught Ichigo this path certainly to increase the chances of countering Yhwach, to save Masaki, and to fulfill the compensation to Ichigo.
But the deeper reason was to pave the way for himself.
In his view, the Tsunayashiro Clan's Ancestor was a fusion of Shinigami and Hollow, and the Soul King was a fusion of Quincy and Fullbring.
If these four soul powers could be perfectly fused, the ultimate evolution of the soul could surely be achieved.
This was the path Setsuna had planned for himself.
But his power was far too immense. The risk of achieving this fusion was extremely high, like turning a giant ship around in a narrow channel… a slight mistake could lead to the destruction of the ship and the death of its crew.
In contrast, Ichigo was like a just-launched small boat with a relatively simple structure.
The 'seeds' of these four powers within him were all in their primary states, making the difficulty and risk of fusion much smaller.
By letting Ichigo explore this path first, he could observe and record from the sidelines, using Ichigo's successes or failures as 'road signs' for his own potential future attempts.