Death of Rōran

The Hōgyoku continued to tremble and hum, drawing in the immense energy of the Dragon Vein like a magnet. The chakra flowed endlessly, as though something deep within the Hōgyoku was pulling it in with a ravenous hunger.

Soon, the once faint blue light of the Hōgyoku began to intermingle with a vibrant golden glow. This strange, otherworldly light bathed Aizen's body, sparking an incredible transformation at the genetic level.

As the golden energy flooded every cell within Aizen, he could feel his entire being rejoicing. Every fiber of his body, from his bones to his muscles, was undergoing a profound and irreversible change.

The process stretched on for what seemed like an eternity—an hour of agonizing evolution. By the time the Hōgyoku had consumed nearly all the energy from the Dragon Vein, Aizen's transformation had reached its final stage.

...

With the completion of the transformation, every single cell in Aizen's body now emitted a radiant golden light, as though each was a tiny star in a vast, miniature universe contained within him.

Simultaneously, an overwhelming surge of vitality burst forth from Aizen's form. His strength, durability, senses—everything had advanced far beyond its previous limits.

By his own calculations, Aizen knew that his current physical abilities had reached such a level that opening the Seventh Gate of the Eight Inner Gates would feel effortless, as though it were mere child's play. This immense vitality—the hallmark of the Senju Clan's Sage Body—had now become his own.

However, achieving this legendary Sage Body would not have been possible were it not for the unique combination of factors: Aizen's own Senju bloodline, the genetic material absorbed by the Hōgyoku from Senju Ryuken and Senju Nawaki, and the tremendous power of the Dragon Vein. Even with the chakra of Asura, it required these extraordinary conditions for Aizen to evolve into a being with a Sage Body.

At the same time, this transformation broke through the limits of Aizen's chakra reserves. Where his chakra had once been constrained by the natural limits of the human body, those restrictions were obliterated in an instant.

As the last remnants of the Dragon Vein's energy were absorbed, Aizen's chakra reserves began to skyrocket. His chakra surged to the level of an Elite Jōnin almost immediately, filling him with unimaginable power.

But that was only the beginning.

Pfft...

A deep, resonant sound echoed from within Aizen's body as his chakra and natural energy continued to rise

In the ninja world, attaining the level of Kage was one of the hardest and most significant milestones on the path to becoming a top-tier shinobi. Even with the talents of Aizen and Minato, reaching this level would have normally taken years—perhaps seventeen or eighteen—of intense training and experience.

However, thanks to the unparalleled power of the Sage Body, Aizen had ascended to this level in mere moments.

It was undeniable—the Sage Body was an absolute, terrifying advantage.

With this newfound elevation, all of Aizen's abilities had advanced once again.

At this moment, Aizen's mastery of Kendō had evolved to the level of Sword Intent. This meant that he could now summon the full power of his sword techniques at will, an ability only achieved by the most skilled and disciplined warriors. Even more terrifying, with the enhancement of his Sword Intent, he could now achieve the destructive power of an S-rank ninjutsu with just one percent of his energy. Previously, this would have required ten percent of his strength.

It was impossible to fathom the level of devastation Aizen could unleash by harnessing ten, twenty, or even one hundred percent of his full power. And this was without factoring in the combination of his Reiatsu (spiritual pressure) and the Sage Body.

At this point, Aizen's overall combat abilities had surpassed the level of a Kage, elevating him to the realm of Super Kage. Unlike others, such as Hatake Sakumo, who could only briefly tap into Super Kage-level strength, Aizen's Sage Body provided him with limitless stamina and chakra recovery. This meant he could engage in combat at full strength for prolonged periods, potentially fighting for days without tiring.

More frightening still was Aizen's adaptability and versatility. His all-around combat prowess was second to none, and he was capable of taking on even the most powerful Super Kage-level opponents head-on. If necessary, he could push himself to the limit and challenge even the strongest shinobi without hesitation.

But there was more.

In addition to his newfound powers, Aizen had also awakened the legendary Wood Style (Mokuton). Unlike the incomplete version wielded by Yamato, Aizen's Wood Style was the real deal, enhanced by the raw vitality of his Sage Body. However, this power was still in its early stages, and it would take time to fully develop it to the level of Senju Hashirama, the First Hokage.

Despite the potential of Wood Style, Aizen viewed it as a secondary ability, one to be used for dealing with lesser enemies. His other powers far outstripped it, but he still intended to master Mokuton out of practicality. After all, even small tools could serve a purpose in battle.

Not long after Aizen had ascended to the Kage level, a strange and volatile fluctuation began to radiate from his body. The fusion of his Sage Body with his powerful soul, enhanced by Kendō and natural energy, created an unstable energy magnetic field that affected the surrounding area for miles.

The sky above Rōran darkened as storm clouds gathered, casting deep shadows over the entire kingdom. The pressure in the air dropped sharply, and a sense of overwhelming dread filled the hearts of the Rōran people. It was as though they had been transported back to a time of chaos and primitive fear, where the vastness of the world rendered them powerless.

Every citizen felt it—an impending doom, as if their very existence had been seized by a higher power.

If any seasoned shinobi had been present, they would have immediately recognized the significance of this phenomenon. The birth of such a powerful figure always heralded a period of bloodshed and war. Historically, the rise of warriors of this caliber would inevitably plunge the world into turmoil, with mountains of corpses and rivers of blood marking their ascent.

In the original events, when Uchiha Madara was resurrected using Impure World Reincarnation, a similar disruption occurred because he initially couldn't control his overwhelming power. Now, the entire kingdom of Rōran found itself gripped by a similar terror.

Amidst the growing panic in Rōran, Aizen remained calm, focusing on controlling the energy spilling uncontrollably from his body. Despite the massive power flowing through him, it didn't take long for him to rein it in.

Within a quarter of an hour, the chaotic energy had been contained.

Aizen took a moment to savor the raw, surging chakra coursing through him. The power he now possessed was intoxicating, a force that seemed to place the world itself under his command.

He closed his eyes, letting the sensation wash over him, an expression of sheer satisfaction crossing his face.

"At this point," Aizen murmured, "there are very few left in this world who can even approach my level…"

Yet despite his immense power, Aizen remained focused and clear-headed. He knew that while he had reached a new level of strength, there were still ancient powers, such as the Six Paths-level warriors, that remained beyond his current reach. Even Senju Hashirama, the God of Shinobi, could present a challenge if they had clashed during the Warring States era. Aizen was not one to let arrogance cloud his judgment.

Careful planning would still be essential for the next steps of his grand design.

But first, he needed to finish what he had started in Rōran.

Even though he had no reason to fear Konoha or its forces at this point, Aizen still required Konoha's resources for the next phase of his plan. Thus, the matter of the Dragon Vein—and its acquisition—had to be kept secret.

No one from Rōran could be allowed to survive.