Regarding the natural energy that is ever-present yet elusive in the shinobi world, Shinji held it in high regard within his heart.
The methods to elevate a shinobi's strength to its utmost limit boil down to two.
The first is to undergo various means to achieve "Ōtsutsukification."
Shinji's current pursuit of the Rinnegan is, in essence, a proactive form of "Ōtsutsukification," aimed at surpassing the strength ceiling of ordinary shinobi.
After all, the Ōtsutsuki clan possesses mastery over cosmic travel, planetary colonization, and other feats far beyond the current technology of the shinobi world.
Thus, the closer one gets to the Ōtsutsuki, the higher their strength ceiling becomes.
As a descendant of the Sage of the Six Paths and a member of the Uchiha clan, Shinji naturally treads this path.
The second method is to master natural energy.
In the shinobi world, shinobi who have mastered sage techniques are few and far between. The First Hokage and Jiraiya-sensei are prime examples.
Without exception, those who master sage techniques start at least at Kage-level strength.
The First Hokage, already a super Kage-level shinobi, broke through his strength ceiling upon activating sage techniques, becoming nearly the strongest below the Six Paths level!
In the battle at the Valley of the End, Uchiha Madara, wielding the Eternal Mangekyō Sharingan and controlling the complete Nine-Tails, faced the First Hokage, who unleashed the sage technique True Several Thousand Hands. Madara, with his Susanoo and the complete Nine-Tails forming the ultimate technique Majestic Attire Susanoo, was utterly crushed, unable to even fight back!
The gap was so vast it was practically a slaughter!
Keep in mind, as the reincarnation of Indra Ōtsutsuki and bearer of the Eternal Mangekyō Sharingan, Uchiha Madara was a bona fide super Kage-level powerhouse.
Thus, Shinji actually understands the value of the Cursed Seal better than Orochimaru. However, his time is too constrained. Advancing the Rinnegan Plan and the Tenseigan Plan has already consumed all his energy, leaving no room to pursue the Sage Technique Plan.
Fortunately, his Rinnegan Plan is now inches from perfect completion, and the Tenseigan Plan is nearing its end. This has gradually sparked his interest in analyzing natural energy and mastering sage techniques.
…
Leaving aside Shinji's careful study of the Cursed Seal chakra extracted from Sasuke, new changes unfolded on the battlefield.
Sasuke, having activated the Cursed Seal, did not remain in Gear One. Instead, he fully released control over the Cursed Seal, letting it spread across his entire body.
In an instant, his skin darkened, his hair grew longer, and a pair of bizarre, palm-like fleshy wings sprouted from his back! "Sasuke!?"
Sensing the chilling, ominous chakra emanating from Sasuke, Sakura's eyes involuntarily welled with worried tears.
Naruto shouted even louder, "Sasuke, don't do it! Granny Tsunade said that kind of power isn't something you can control right now—it'll corrode your body!"
"Idiot, you're facing me, and you still have the nerve to worry about someone else!"
Sakon and Ukon sneered, kicking Naruto away with a single blow.
Fully immersed in Gear Two, Sasuke cast a sidelong glance at the flung Naruto, his face bearing an unprecedentedly cold expression. "Compared to being corroded, I sure hate the powerless version of myself even more."
Jirōbō roared at the other Sound Four members, "Stop messing around! This guy's entered Gear Two too. I can't handle him alone—hurry and help me!"
Sasuke lifted his hands, inspecting them as he murmured, "So this is called Gear Two, huh?"
Jirōbō's face darkened. "Even if you've entered Gear Two like us, you alone can't take on all four of us! You're dead today!"
Ah!
Suddenly, a scream from Sakura echoed nearby.
Sasuke glanced over and saw Tayuya strangling Sakura's neck before casually tossing her aside like trash.
Tayuya then pulled out a flute and activated her Cursed Seal. Horns sprouted from her head, her skin darkened, and she entered Gear Two.
Elsewhere, Sakon and Ukon, who had kicked Naruto away, also activated their Cursed Seal with cold expressions.
As inky patterns spread across their body, entering Gear Two, their form began to split. Ukon, previously dormant within Sakon, emerged from his body, becoming a separate entity.
Surveying Jirōbō, Tayuya, and the now-separated Sakon and Ukon, all having activated their Cursed Seals, Sasuke remarked, "As expected, you all can do it."
Undoubtedly.
Though he hadn't seen it with his own eyes, Sasuke knew that Kidōmaru, hidden in the treetops, must have activated his Cursed Seal as well.
The fact that all four Sound shinobi possessed this ability was no coincidence. The mysterious figure who implanted the Cursed Seal in him was, in all likelihood, from the Hidden Sound Village! "In return for granting me this power, I'll tear you apart!" Sasuke thought darkly before turning to the Sound Four. "As for you lot, prepare to die!"
"You think you can take on all four of us?"
Tayuya sneered as she formed hand signs, activating a summoning technique.
Bang. With three puffs of white smoke, three colossal figures appeared behind her. These towering, house-sized giants were her summoned beasts, the Three Demons.
Ukon shouted, "Quit talking and kill him already!"
Swish. Before Ukon could finish, Sasuke turned into a blur, charging at Ukon. He seized Ukon's neck and dragged him out of the battlefield in one swift motion.
"What!?"
Not just Tayuya and Jirōbō, even Sakon couldn't react in time.
Moments later, the three snapped back to their senses and chased after Sasuke in the direction he'd taken Ukon.
Soon, they stopped before a massive tree.
Beneath this tree, which would take several people to encircle with outstretched arms, Sasuke, holding Ukon, turned to face them. "So slow."
"Damn it!"
Sakon gritted his teeth.
Ukon, held in Sasuke's grip, no longer bore his earlier arrogance. His head lolled to the side, lifeless—his neck clearly crushed by Sasuke.
Moreover, a noticeable dent marked Ukon's chest. It seemed Sasuke, wary that breaking his neck might not suffice, had delivered a crushing blow to Ukon's heart, shattering it completely!
Tayuya and Jirōbō's faces darkened as well.
Ukon in Gear Two was not much weaker than them in physical techniques, yet he had died so inexplicably at Sasuke's hands. This showed that Sasuke's speed and strength had already outstripped them by a margin! Casually dropping Ukon's corpse, Sasuke said, "I recall you guys mentioning something about hunting me? Hmph, 'hunting' is a nice word, but you're the prey!"
Sakon roared in fury, "You damned bastard!"
Tayuya held Sakon back. "Don't let him provoke you. We still have the numbers advantage. Gear Two can't be sustained for long. If we stall him, we won't be the ones dying today!"
"Is that so?"
Sasuke's lips curled into a smirk as he lunged forward.