In the original storyline, Sasuke's Rinnegan ability, Amenotejikara, was an absolute god-tier move. But unfortunately, he only ever had one Rinnegan. Even in Boruto, we never saw what the full power of dual Rinnegan could do with that technique.
What's more, Amenotejikara clearly came from the Sage of Six Paths, it didn't really match Sasuke at all. He never had any real aptitude for space-time ninjutsu; the ability was just given to him as a counter to Madara Uchiha.
Look at Madara's ability: as a supreme narcissist, his Rinnegan power manifested as five invisible clones of himself. The peak of self-worship.
Sasuke, despite his cold and aloof exterior, was in truth hot-blooded, fiery, and consumed by revenge. He thirsted for power more than anything. So his Rinnegan ability was far more direct and destructive, it was called Tendō Ōmiya (Celestial Imperial Domain).
It was a domain-type ability. Once activated, within a certain radius, all energy, including the opponent's chakra, came under Sasuke's control.
Hashirama was always known for brute force: overwhelming the battlefield with giant Wood Style techniques. But people often forgot, he wasn't born invincible.
He clawed his way up through the Warring States era's bloody battlegrounds. His talent as a ninja was no less than Madara's.
So the moment Sasuke activated Tendō Ōmiya, Hashirama instinctively sensed danger and immediately wrapped himself in a Truth-Seeking Orb armor.
That was one of the few methods capable of resisting the domain's effects. Normal shinobi without this kind of defense wouldn't stand a chance. Within the domain's range, Sasuke could kill them with a mere thought, instantly.
Hashirama quickly demonstrated his masterful control over the Truth-Seeking Orbs. Unlike Obito, who barely managed to use them as armor in the original story.
Hashirama could effortlessly shape them into full armor, covering his body and isolating himself from the domain, allowing him to engage Sasuke in battle.
Aoba stood nearby but didn't intervene. This fight was primarily a test, to see what Sasuke could do.
Truth be told, after years of observation, Aoba had realized: Sasuke's actual talent as a ninja was quite a bit below Itachi's. Even as the reincarnation of Indra, that gap wasn't fully closed.
So far, Aoba had only met three shinobi whose talent genuinely amazed him: Madara, Minato, and Itachi.
Hashirama was harder to judge, his natural-born advantages made it difficult to fairly evaluate his raw talent. But the fact that his innate power was so overwhelming… that in itself was a kind of talent.
Right now, even though Sasuke had seized control over all chakra and natural energy within the domain.
Hashirama could still create Truth-Seeking Orbs using only the chakra within his own body and launch real, effective attacks.
The two clashed with black blades in the air. Sasuke had also shaped a Truth-Seeking Orb into a sword and closed in for melee combat.
Just that action made Aoba shake his head. Sasuke wasn't untalented, but compared to Itachi, he had one critical flaw:
Pride. Or rather, he was kind of a tsundere.
In the original series, Sasuke never blamed others or the world. When he won a fight, it was Uchiha pride. When he lost, it was his own weakness.
But every time he had the upper hand, he couldn't help but start flexing. That tendency led to some of the most famous blunders in the story, like the meme-worthy "the rain has cleared, the skies are blue again… and Sasuke thinks he's him again."
Even in this timeline, after years of careful teaching by Aoba, Sasuke had mostly corrected that behavior. But the moment he faced Hashirama, it all came rushing back.
Inside the domain, Sasuke's energy manipulation far surpassed Hashirama's. He could control surrounding chakra, natural energy, even the bioelectricity inside living beings, wearing down his opponent.
Since energy around them was suppressed, Hashirama couldn't enter Sage Mode using natural energy. Even forming a single Truth-Seeking Orb cost him ten times as much chakra as it cost Sasuke.
Every bit of chakra that leaked from his body would be instantly hijacked by Sasuke. So forming Orbs outside the body became wildly inefficient.
Sasuke had inherited all of Aoba's chakra, within him pulsed a mini Ten-Tails as an energy core. His body was cloaked in the highest-tier chakra armor.
He didn't even need to fight directly. All he had to do was wear Hashirama down from a distance, forcing him to constantly defend with Truth-Seeking Orbs. With enough attrition, Hashirama would fall.
Sasuke was already in an unbeatable position.
But the moment Hashirama charged, Sasuke's blood boiled.
To defeat the God of Shinobi himself? For someone like Sasuke, who loved a dramatic finish, that was just too juicy to resist.
Sasuke's swordsmanship wasn't bad, after all, Aoba was Konoha's top kenjutsu master. But what surprised him was that Hashirama's swordsmanship was just as impressive.
Within a few dozen exchanges, Hashirama had already taken the upper hand.
After several more rounds, Sasuke was forced to use ninjutsu, he blasted Hashirama away with a Shinra Tensei.
But losing the sword duel… made Sasuke visibly angry.
He had received his master's chakra legacy, nearly infinite reserves that made him feel invincible. After awakening the Rinnegan, and a powerful ability like Tendō Ōmiya, he thought even the Sage of Six Paths would be easy to handle.
But now, in his first real battle, he had lost the opening round to Hashirama.
Sasuke's composure cracked.
In a fit of rage, he unleashed his Susanoo.
If you would like to read more...
The novel has be completed (Chp. 362) on the patreon -> SaintXI