These Grim Reaper masks were unique creations from the Hirasaka domain, governed by the God of the Northern Underworld. They were forged from a kind of basic divine material.
After Hirasaka, the God of the Northern Underworld, and the god of the Otsutsuki perished together, invaders such as the King of Hell's clone and the [Death God: Sealing Force] forcibly devoured the original Grim Reaper clones and took residence within these special masks.
By doing so, they reduced their own consumption while steadily feeding on the power left behind by the God of the Northern Underworld.
Originally, they had been scattered across their own respective planets.
However, after Hagoromo Otsutsuki, the Sage of Six Paths, awakened the purest reincarnation power in the entire world, a power even more refined than that of the higher ranks of the Otsutsuki Clan, these Grim Reaper masks were drawn here by instinct.
Only later did the Sage of Six Paths discover the connection between the power of the Grim Reaper and the Rinnegan. From that realization, he imitated the Grim Reaper's stomach and created the Pure Land.
Meanwhile, Yama, whose base abilities far surpassed those of [Death God: Sealing Force], continued to seize this world's power of reincarnation according to the instincts buried within it.
The Uzumaki Clan, descendants of the Sage of Six Paths, inherited part of Hagoromo's research and notes. They traveled across the world collecting these Grim Reaper masks, enshrined them, and gradually developed countless sealing techniques from them.
Brook took every single Death Mask.
After all, even the smallest scrap of meat was still meat.
He started by devouring the twenty four Grim Reaper clones left behind by Hirasaka, using them to strengthen himself.
Then he moved on to devour Yama's clone, the one that held a portion of the power of reincarnation.
But Yama's clone was even stronger than [Death God: Sealing Force], and it possessed an intense instinctive resistance. The backlash nearly caused Brook himself to be assimilated instead.
That fright forced him to make one decision.
He had to grow stronger again, immediately.
So Brook first summoned the complete [Death God: Sealing Force], then fused it entirely with the [Hell God: Jin] form. After combining that with the power of the Hirasaka clones he had already devoured, the whole thing transformed into a brand new existence.
[The New God of the Northern Underworld: Brook.]
Brook had made up his mind.
He would become the new God of the Northern Underworld.
At that point, even the entire Otsutsuki Clan would no longer be enough to frighten him.
In that new form, Brook's ability to fuse and devour became even more terrifying.
He forcibly devoured and merged Yama's clone into himself, taking its reincarnation authority for his own.
That process alone took an entire day.
During that time, he also completely shattered every seal Madara Uchiha had left on the Rinnegan and fused the eyes fully into his own body. The part of Yama's power that had once stolen authority over the Rinnegan was absorbed into Brook's own pair of eyes.
Then the Rinnegan began to evolve again.
Tomoe appeared within the purple ripples, one after another.
A purple Rinnegan with three tomoe.
"There's even a bonus like this?"
Brook exclaimed in delight, almost laughing out loud.
"So this is the reincarnation power Yama's clone managed to snatch."
Then his gaze shifted toward the final two masks, the ones formed from the Soul King's left and right legs.
Just how much power was hidden inside those things?
Brook did not hesitate.
He immediately fused with the Shinigami clone that had been born from the Soul King's left foot. The power inside not only did not resist, it actively merged with him, which made Brook uneasy for a moment.
Could the Soul King really have set him up?
Fine.
At worst, he would just leave this universe himself.
But once he saw how smoothly the fusion was going, he simply pushed through and devoured the clone formed from the Soul King's right foot as well.
At that point, Brook could only trust that Jin, the clone of the Western Underworld God, possessed a stronger devouring and fusion authority than the powers of the other gods, enough to break any trap laid for him.
Once again, endless power surged into his body.
His previously chaotic form began to refine itself.
His body and soul became more harmonious than ever before, and he also obtained the space time abilities that belonged to the Soul King. Even the tiny amount of spatial bloodline he had absorbed from Minato Namikaze was amplified.
Every messy ability he had devoured over the last several days was strengthened and optimized.
Even the Kamui Sharingan disappeared from his arm and fused into the Rinnegan.
Was this the optimization authority that belonged to gods?
Brook felt an unprecedented sense of wholeness.
Before this, he had been nothing but a patchwork existence, both in body and in soul.
Now, after merging the powers of the Soul King's left and right legs, he had finally become a true whole.
"How is this possible? A single Noh Mask Hall actually pushed me all the way to godhood."
Brook stared in shock.
His eyes slowly returned to their normal black color.
Then, with a single thought, they shifted into the red Kamui Mangekyo Sharingan.
Another thought, and they became the purple three tomoe Rinnegan.
He could now freely switch between all of his eye forms at will.
Brook threw aside the black ribbon, used Water Release to create a mirror, and carefully examined his own reflection.
Perfect.
Was this what people called a heaven defying opportunity?
Even Brook himself could hardly believe it.
He had only passed through the ruins of Uzushiogakure on the way to Kirigakure in the Land of Water.
He had never expected the Shinigami masks to hand him such an unbelievable harvest.
This was rarer than finding a secret manual after falling off a cliff.
Was it coincidence?
Or had someone planned all of this?
Brook did not know.
But one thing was certain now.
He had inherited power from all four Underworld Gods.
His strength had already surpassed that of the Sage of Six Paths.
Perhaps he was even beginning to approach the level of the Underworld Gods themselves.
Of course, even the Underworld Gods and the Otsutsuki God only stood at the lowest threshold of true divinity, but that level was still hundreds of times beyond the Sage of Six Paths.
Brook stored all the Masks inside the Kamui dimension, only to discover that the space itself had expanded several times over.
That thrilled him even more.
As he moved, he continued leaving Flying Thunder God formulas along the road, then sped toward the Land of Water in high spirits.
His sensory ability could now cover nearly the entire Land of Fire. As long as he could sense one of his Flying Thunder God formulas, he could teleport across absurd distances.
He remembered that even Minato Namikaze, after being revived with Edo Tensei and blessed with effectively limitless chakra, had nearly collapsed after transferring Truth Seeking Orbs from the battlefield back to the area near Konoha.
Brook, however, now wielded an energy level that surpassed the chakra of the Divine Tree itself.
If he absorbed the complete Ten Tails and Isshiki Otsutsuki, then he felt that he would be able to teleport freely between every marked point on the planet.
In some respects, that might even be faster than a space time technique like [Yomotsu Hirasaka].
Of course, Flying Thunder God still had its own flaws.
[Yomotsu Hirasaka] could cross dimensions at will. It could open portals to Kaguya Otsutsuki's original world, to outer space, or even to the hells of the Underworld.
Flying Thunder God, without a mark, could go nowhere.
It could not even sense Kamui Space, let alone the Origin Sphere dimension or the realms of the Underworld itself.
Brook felt the power in his body surging endlessly, and a violent urge rose in him.
He wanted to hunt down the Otsutsuki Clan.
He wanted to devour them one by one and keep growing stronger.
He even wanted Isshiki Otsutsuki to send out a distress signal and summon the rest of his clan to this planet, so Brook could hunt them down one after another.
-------------
Brook floated through the sky, flying at top speed toward Kirigakure in the Land of Water.
Whether it was the natural levitation granted by Six Paths level power or the [Earth Release: Super Light Weight Rock Technique] taken from the Third Tsuchikage, Onoki, Brook could now travel through the air at tremendous speed.
And his current combat power had already broken past the sixth tier. Compared to before, he was no longer on the same level at all.
In less than half a day, he crossed the sea and entered the territory of the Land of Water.
At present, Kirigakure had entered its highest state of alert because of the invasion by an unknown powerhouse. Every ninja clan and every ANBU squad in the village had been mobilized to search at full strength.
The enemy consisted of only three people, yet they had destroyed nearly half of Kirigakure. Since the founding of the village, such a thing had never happened before. The sheer horror of it had shaken the entire Hidden Mist Village.
One of the intruders possessed the Mangekyo Sharingan. Another wielded a terrifying repulsive force. A third could even use Wood Release. With that combination, Kirigakure had immediately concluded that the attackers were Konoha shinobi.
The Fourth Mizukage, Yagura Karatachi, had already sent a message to the Daimyo of the Land of Water, expressing furious outrage over Konoha's unannounced invasion.
The Land of Earth and the Land of Lightning were already attacking the Land of Fire. Yet even under those circumstances, Konoha still dared to provoke Kirigakure. It was simply unforgivable.
The higher ups of Kirigakure jointly petitioned the Daimyo of the Land of Water to declare war on Konoha.
In their eyes, it was impossible for Konoha, after losing the Nine Tails Jinchuriki and two Kage level fighters, to still fight three great nations at once.
While Kirigakure assembled its forces, it also continued searching for the invaders. Once those three were eliminated, Kirigakure would launch a full offensive and join the siege of Konoha.
In an underground space near the Hidden Mist Village, Obito Uchiha was recovering with the help of White Zetsu Tobi.
He had never expected Kirigakure's combat strength to be this troublesome. He simply could not bulldoze through it.
That so called Lord Death had been late by several days, far past the agreed time. He was maddeningly unreliable.
On the appointed day, Obito had already revealed himself ahead of schedule and charged out to wreak havoc in Kirigakure. He activated Susanoo and fought the Mist ninja for half a day, exhausting almost all of his chakra.
Brook still had not arrived.
In the end, Obito was forced to flee in embarrassment. Even with Madara Uchiha and Tobi helping him withdraw, he still suffered serious injuries before barely escaping alive.
"Damn it! That liar! That bastard still hasn't shown up!"
Obito cursed bitterly. Parts of his face and body had been corroded, and even with the recovery power of Tobi's Hashirama cells, it had taken him more than a full day to slowly heal.
He had not expected that blue clothed girl with two bloodline limits to be so strong. He had truly underestimated her.
At first, all his attention had been on the Fourth Mizukage, Yagura Karatachi, the Three Tails Jinchuriki. He thought controlling Yagura would solve everything. But to his surprise, Yagura was extremely wary of the Sharingan, making it impossible to control him so easily.
With the combined support of Kirigakure's major bloodline clans, such as the Kaguya, Yuki, and Hozuki, even Obito's Susanoo had been shattered at one point.
Add in the remnants of the Seven Ninja Swordsmen of the Mist, the new generation of swordsmen, and Kirigakure's large number of elite ANBU, and Obito had been driven into a miserable retreat.
While Obito was gritting his teeth and cursing under his breath, Brook had already sensed the Flying Thunder God marks on Madara and Obito.
The moment he arrived, he heard Obito's complaints.
Obito froze.
When he saw Brook's mocking gaze fall on him, his face immediately stiffened and his scalp went numb.
"Greetings, Lord Death!"
Obito instantly dropped to one knee, cold sweat pouring down his back and his heart pounding wildly. He could only pray that Brook had not heard what he just said, or at least that he would not bother to hold it against him.
"From now on, call me Lord Brook."
Brook ignored Obito's fear. In his eyes, Obito was just a tool. There was no need to waste time soothing him.
He released Animal Path Danzo from Kamui and had him stand beside Deva Path Madara.
"This time, your performance disappointed me. But for the sake of these corpses, I'll spare you."
Brook spoke calmly, because he had already seen the bloodline corpses Tobi had collected, including members of the Kaguya, Yuki, and Hozuki clans, along with most of Kirigakure's notable bloodline families.
At least Obito had not been completely useless.
While Obito and Deva Path Madara rampaged through the village and drew all the attention, White Zetsu Tobi had secretly gathered the bodies.
Brook immediately began fusing with and devouring those bloodlines, refining his Northern Underworld divine body a little more with every corpse. Every ability and every bloodline was something to be accumulated piece by piece.
The Kaguya clan's [Shikotsumyaku], the Corpse Bone Pulse, clearly had some connection to Kaguya Otsutsuki's [All Killing Ash Bones]. After all, the Kaguya clan was also descended from the Otsutsuki bloodline.
Their hairstyle, facial structure, and even their eyebrows carried traces of Kaguya Otsutsuki herself. Even their clan name was enough to prove their origin.
Brook fused with and devoured those corpses right in front of Obito, frightening him badly.
The next moment, the entire underground chamber grew cold. The temperature plummeted and frost began to spread.
"Ice Release is decent. The Corpse Bone Pulse is a bit lacking. If it could evolve into [All Killing Ash Bones], that would be much more interesting."
Brook chuckled, comparing it in his mind to Kuzan's Ice Ice Fruit. Of course, it could not match that kind of power yet, but it still had room to develop. At the same time, a white bone blade appeared in his hand, though the power it carried was still somewhat lacking.
"The Hydrification Technique is somewhat similar to Logia style elemental transformation."
Brook continued testing the bloodlines he had just taken. Devil Fruit users feared seawater, while the Hozuki clan's water transformation technique was extremely vulnerable to Lightning Release chakra. In some ways, it felt similar to elemental powers meeting Armament Haki.
This was a bloodline that Lightning Release naturally countered.
The chakra fruit born from the Ten Tails God Tree had given rise to the entire chakra system. Then, through generations of descendants beneath Kaguya Otsutsuki's line, it had evolved into countless elemental abilities and bloodline variations.
Many of those attributes and powers had already grown beyond even the original control of the Otsutsuki clan.
Still, the energy level of the Otsutsuki remained so high that it could suppress most chakra based ninjutsu directly. Most bloodline limits simply were not a real threat to them.
When Obito watched Brook devour and fuse those corpses, gaining their bloodline abilities one after another, his eyes filled with both fear and greed.
He feared that one day Brook would kill and devour him too. After all, he had already seen far too much of Brook's secrets.
But at the same time, he desperately longed for that same horrifying ability, the power to grow stronger without limit by devouring everything in front of him.
Even White Zetsu Tobi was trembling, lying prostrate on the ground in submission, terrified that Brook might turn his attention to him next.
It had never seen a human this terrifying before.
Compared to this man, even its former master, Uchiha Madara, seemed far less frightening.
.....
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