When a human kills a god, devours its power, gains its Authority, and is thereby reincarnated as a Campione, besides gaining an Authority related to that god, he (or she) also obtains many other traits.
For example, mastering the Thousand Languages—this is an ability that allows one to rapidly grasp foreign languages. All Campione possess this ability, and wherever they go, they will not encounter communication issues.
In addition to Thousand Languages, a Campione also gains night vision upon reincarnation, and their physical body becomes extremely durable. Their bones are harder than any alloy in the world, muscle fibers are nearly impossible to tear, and they gain abilities more potent than the effects of adrenaline—the bleeding stops instantly, and pain becomes dulled. As a result, even when injured, their combat capabilities are scarcely diminished.
The Magical Power within a Campione is also several hundred times stronger than that of ordinary magicians. By simply enhancing the flow of Magical Power within their body, they can become immune to external magic, spells, and other forms of mysticism. Their resistance to magical forces is so strong that even beneficial techniques will be repelled unless directly implanted into the body—otherwise, they will have no effect.
Moreover, when sensing the approach of battle, the presence of a god, or impending danger, a Campione's body will naturally adjust to an optimal state. Their fighting spirit will surge forth automatically, morale will rise dramatically, allowing them to unleash two hundred percent of their strength.
It is precisely because of these various abilities that Campione are able to surpass the realm of mortals, reaching the stage of confronting gods head-on. Even when facing beings stronger than themselves, they can rely on instinct and primal senses to exhibit extraordinary performance and ultimately achieve victory against the odds.
These are the benefits of reincarnating as a Campione, and they are rewards granted only upon the first successful god-slaying.
After becoming a Campione, even if one slays a second, third, fourth, or countless more gods, the only thing gained is additional Authorities—no other powers will be obtained.
Therefore, the ritual of slaying the first god is of utmost importance.
Kaiser, who had known this from the beginning, naturally wanted to maximize the benefits of this ritual.
After obtaining the Hōgyoku, although his Spiritual Pressure had surpassed its limit and he had acquired Hollow powers, he had yet to undergo a true evolution powered by the Hōgyoku.
In the original story, Aizen, after obtaining the Hōgyoku, evolved multiple times and thereby transcended both Shinigami and Hollow, reaching a new realm and becoming a new form of life. Kaiser had not yet reached that point.
Therefore, he had long since resolved to seize this opportunity to utilize both the Hōgyoku and the Circle of Usurpation together to carry out a complete and thorough evolution.
Given the choice, after becoming a Campione, he would naturally eliminate certain drawbacks, retain certain benefits, and even enhance them to become better and stronger, seeking to push this reincarnation to its peak.
For instance, the resistance of a Campione—which indiscriminately repels all mysticism, including both beneficial and harmful magic—must be modified accordingly.
His physical body must gain an automatic recognition function, allowing it to retain beneficial powers and repel harmful ones. That would be the optimal evolution.
Moreover, for the post-reincarnation physical body, it isn't enough to merely become extremely durable, with bones harder than any alloy and muscle fibers hard to tear. Since he also possessed High-Speed Regeneration and Hierro, all these body-targeting modifications could be integrated to forge his body into something immensely robust both inside and out.
Thousand Languages, on the other hand, could be discarded. As the Librarian of the Fantasy Library, Kaiser inherently understood the major languages of the fantasy worlds and had no issues with communication, so the power used to form Thousand Languages could be redirected into enhancing the body, making it even stronger.
As for night vision—Kaiser had already gained that ability after acquiring the Hōgyoku, so the power forming this ability could also be redirected elsewhere to be reinforced.
Of course, during this process, Kaiser also aimed to gain new abilities.
He had long lacked powers related to mental or sensory faculties, which resulted in his inability to break through Kuroka's illusion in the High School DxD World, and being unable to escape the complete hypnosis of Kyōka Suigetsu in the Bleach world.
He could go without such abilities—but at the very least, he needed abilities that could render him immune to them.
With the Hōgyoku, he could evolve himself in the direction he wished, acquiring the abilities he needed—this undoubtedly filled a major gap in his arsenal.
Given this, Kaiser paid special attention to his Magical Power resistance.
He planned to use the power of the Hōgyoku to forge it into an absolute resistance against mysticism.
In doing so, all forces—whether offensive, or ones targeting the mind and five senses—would be regarded as negative and repelled.
If not for the fact that the power of the Hōgyoku was limited, and the divine power seized by the Circle of Usurpation was also finite, he even wanted to evolve himself to possess something like the Eyes of Insight.
Unfortunately, due to limited power, Kaiser could only push forward in as ideal a direction as possible—not striving to see through everything, but at least ensuring that he would remain unaffected and never be toyed with.
And so, under the joint effect of the Hōgyoku and the Circle of Usurpation, Kaiser's reincarnation began to evolve toward something inhuman.
As for the Authority gained after slaying the god, Kaiser also made his choice.
"Whoosh!"
A spear suddenly appeared before Kaiser and was grasped in his hand.
The shaft of the spear was made from the branches of the World Tree, covered in ancient and mysterious patterns.
The tip of the spear was inscribed with rune symbols, emanating an air of divinity.
This was not like the True Longinus, a long spear meant for melee, but a thrown spear.
Its name was Gungnir, also known as Gungnir—a Spear of Fate that brings victory upon being thrown, guaranteed to hit and guaranteed to win.
"As expected, I can choose this spear as my Authority."
Looking at this legendary divine tool, Kaiser could not conceal his inner excitement.
Generally speaking, what kind of Authority a Campione obtains depends on luck, personality, disposition, and abilities. The process is entirely random and cannot be chosen.
However, in the original story, the protagonist was once granted, under Pandora's permission as the master of the Circle of Usurpation, a single, one-time opportunity to choose his Authority.
This implies that the one who controls the Circle of Usurpation can determine what Authority is given to a Campione.
That it hadn't been done previously was simply because Pandora had no desire to do so.
She probably believed that only the Authority naturally matched through the ritual was the most suitable for the individual.
But Kaiser certainly wouldn't follow that route.
He knew very well what he needed and what kind of Authority would benefit him the most.
Thus, without hesitation, he chose Odin's spear.
This spear was not only a divine weapon, but also a materialized form of Authority.
Unlike the True Longinus, Boosted Gear, Divine Dividing, and other sacred tools created by gods for humans to use, this was a weapon personally wielded by a god—imbued with Divinity, possessing Divinity and Divine Power, a spear that once accompanied its wielder through mythic battles, struck down giants, and fought the Vanir gods!
A Spear of Inevitable Victory and Destiny, capable of interfering with fate—in terms of threat to enemies, this spear surpassed even the True Longinus in certain respects!
"Buzz!"
Kaiser directly activated his Authority and initiated the recognition process for the Gungnir.
Because it was the materialization of the Authority he had just obtained, the process of recognition was almost instant, turning the Gungnir into a streak of light that flew into Kaiser's body.
At the same time, Kaiser's reincarnation ritual and first evolution were completed. The Hōgyoku within his body ceased its rotation, and the Circle of Usurpation above his head also drilled into his body, vanishing from above him.
Kaiser sensed himself and confirmed that his body had indeed undergone a transformation from inside out—not only powerful but also extraordinarily resilient, full of strength.
The Magical Power within his body had also increased severalfold, making Kaiser's already overwhelming Magical Power utterly inhuman.
If a normal Campione's Magical Power is hundreds of times greater than that of ordinary magicians or spellcasters, then his is at least a thousand times—two to three times stronger than an average Campione.
"With my current self, even if I don't use any weapons, I can easily crush Demon Lord-class existences, right?"
Kaiser had that confidence.
At the very least, facing opponents like Vali and Azazel—even if they used sacred gears or artificial gears in Balance Breaker form—Kaiser was confident he could win barehanded.
Against someone like Genryūsai Shigekuni Yamamoto, he now felt he could win effortlessly without drawing his sword.
"So this is the benefit of God-Slaying?"
Kaiser could hardly wait to summon the second Heretic God.
Not just to gain another Authority—but to test his current strength.
However...
"Not just yet."
Kaiser lowered his head and looked at the city below.
Signs of chaos still lingered there—like the aftermath of a disaster.
After Kaiser killed Odin, the storm disappeared, the ghost army and the oppressive black clouds vanished as well, but the tsunami that had been stirred up still remained—only the external force behind it had been removed.
The tsunami surged into the city, and the damage it caused was self-evident.
Fortunately, it seemed that forces from the mystical side had intervened, eventually stopping the tsunami. Though it still caused damage, it wasn't as devastating as it could have been.
This stirred some feelings in Kaiser.
"No matter how much you avoid the crowd, when divine and Campione-level powers appear, it's still impossible not to impact the world."
That was simply the consequence of too much power, regardless of intention.
Even if Odin hadn't approached the city and the two had fought at sea, it could still have affected ocean currents, giving rise to typhoons, hurricanes, tsunamis, floods, and other natural disasters.
In the face of gods and Campione...
"Humanity is just too insignificant and too fragile."
Shaking his head, Kaiser took a step forward—and vanished from mid-air...