Directly devouring the eyeball would mean suffering a brutal, foreign power in a short amount of time, just like Ōtsutsuki Urashiki.
How much of that power could ultimately be retained was unknown—there was even the risk of permanent cognitive damage.
As for surgical transplantation, while he could freely control his own cells, the Nine Tomoe Rinnegan was, after all, an imported product. Its effects might not even compare to the incomplete fruit energy that Kaguya had yet to fully absorb.
In other words, it was secondhand goods… of secondhand goods.
Thus, he made an extremely bold decision—
To use the divine technique 〖Heaven-Reversing Devour〗 awakened through the Rule Devouring of all Uchiha bloodlines—a technique branded into the blood itself.
And to combine it with the newly fused 〖Five Elements Cycle〗, a system of rules centered around balance and coordination among multiple Nature Affinities.
With both divine techniques stacked together, he would absorb it completely.
"Oh right, my Limbo Clones can use this power too!"
The more he thought about it, the more convinced Uchiha Kirin became that this plan was feasible. After all, the source of 〖Heaven-Reversing Devour〗 was the Uchiha, the fallen gods, and even the Divine Tree itself!
Using it to absorb the power of the Rinnegan Sharingan was essentially…
Reforging it from the ground up.
With the plan decided,
Uchiha Kirin summoned all six Limbo Clones back with a single thought.
The clones gathered around his main body,
Activating the Breathing Art of the Sage Path in unison, syncing their breaths until a powerful suction force burst forth, drawing in nearly endless stellar energy—
Used as fuel to activate multiple divine techniques.
In the past, just activating 〖Heaven-Reversing Devour〗 once nearly drained him into unconsciousness after swallowing a single item.
But now, with his body having undergone multiple evolutions,
Six clones and the main body together activated seven vortexes of 〖Heaven-Reversing Devour〗, each connecting to a minor world.
Adding the tremendous energy consumption of 〖Five Elements Cycle〗,
They surrounded the Rinnegan Sharingan at the center—
And activated everything at once.
"Success!"
The ultimate Sharingan with nine tomoe finally began to break down. Threads of power turned into red mist and were drawn into Uchiha Kirin's body.
The energy flowed throughout him and ultimately settled into his eyes!
As he felt his Ocular Power surge, Uchiha Kirin was overjoyed. But with the successful absorption, an unexpected danger arrived as well.
Because this eye didn't just contain near-infinite Ocular Power—it also held power from the 〖Amenominaka〗.
And that power was connected to the Core dimension that had been shattered during his battle with the Sage of Six Paths.
That, too, was a world!
Thus, under his peerless refining and absorption power,
The Core dimension began to collapse. And due to the world-linking force of 〖Heaven-Reversing Devour〗, the energies of both worlds began to draw each other in.
The two worlds were on the verge of collision.
"This can't happen… I absolutely can't let them collide!"
Kirin's heart turned cold. The minor world connected to Kamui had already become deeply linked to his life force.
Not only that, but as its power had grown, its special abilities had begun to manifest—
And in the future, it would become the key to his transcendence beyond this universe!
He couldn't afford to lose it!
The Limbo Clones all moved to block the collision of the two worlds.
But it was like trying to stop a flood with a cup—completely useless!
These were entire worlds, each with internal rules, operating independently and self-sustaining.
Even inferior divine realms were kept by gods as their last resort—
Let alone full-fledged worlds. If they collided, even someone as powerful as Uchiha Kirin would be doomed!
And at this point, the two worlds were so close that the gravitational pull between them had become overwhelming.
Kirin's main body activated the tenth level of the 〖Battle Saint Scripture〗, followed by the Eight Gates, and even attempted the never-before-stacked 〖Seven Heavens Breathing Technique〗.
Three secret arts layered on top of each other, forcibly driven by the Breathing Art of the Sage Path.
Even with his countless evolutions, and his lifeform level having long surpassed human limits—
He was still pushed to the brink.
"Shinra Tensei… Shinra Tensei…"
With six clones at his side, he poured all his might into manipulating repulsive force, desperately trying to push the two worlds apart.
But the convergence was irreversible.
"I'll just gamble it all then!"
Seeing no hope, Kirin gritted his teeth. If he died, he could just restart anyway!
He just hadn't personally experienced death yet, that's all.
He quickly completed the absorption of the Rinnegan Sharingan.
As his eyes swelled with terrifying power, he acted in one swift motion. The six clones and his main body simultaneously activated 〖Heaven-Reversing Devour〗—
But instead of forming seven separate vortexes like before, they combined their power to tear open a void-black domain in space.
Their goal: to merge the Core dimension into their own world, turning it into nourishment.
It was destined to be an irreversible clash—only one would survive!
The two world energies seemed to gain sentience, erupting into fierce combat.
In terms of comparison, the Core dimension created by Kaguya—formed from absorbing the chakra of the ninja world over countless years—was vastly superior in size and rule structure.
But an ungoverned world, no matter how powerful, was ultimately just dead weight.
What's more, the Core dimension had already been damaged in the previous battle, with a corner shattered and its internal structure beginning to collapse.
In contrast, the minor world evolved from Kamui was small, but had never ceased to be used.
Kirin continuously refined its rules and divine techniques within it, over and over again—perfecting it step by step. Its core structure had even become slightly more resilient than the Core dimension.
With one rising and the other falling, it was the Core dimension and the 〖Amenominaka〗 that ended up being devoured by Kirin and his world!
"It worked!"
Kirin was thrilled. His world's core had absorbed the entirety of the Core dimension, and he had directly gained the powers of Infinite Tsukuyomi and the Amenominaka.
Given time, he would fully digest the power of the Core dimension and make it his own.
However, in the next instant, the core of his Kamui-evolved world could no longer withstand the overwhelming power.
A deafening explosion erupted.
Everything within—Tenseigan, relics, and several crucial prototype Divine Tools—was reduced to powder.
Blood poured from Kirin's seven orifices, and even with the damage split among the Limbo Clones, all of them were severely injured. Only then did he barely cling to life.
Strangely though, the powdered world didn't vanish.
Instead, carrying the scattered energies of the two original worlds, it began to reassemble using the leftover 〖Heaven-Reversing Devour〗 vortex at the center.
However, this would be an incredibly energy-consuming process.
Kirin's body, once robust, instantly deflated like a punctured balloon.
If his energy were to run out, the reformation would halt—and he'd lose any chance of waking up.
Fortunately, the Breathing Art was still running…