To be fair, Vali really was incredibly strong.
His natural conditions were simply absurd.
As a human–devil hybrid, his human bloodline granted him a Longinus, making him the current White Dragon Emperor. That alone was already an outrageous advantage. And yet, his devil bloodline was just as extraordinary, directly inherited from a former Maou. When the two were combined, the benefits were obvious to anyone with eyes.
Longinus weapons were powerful, sure, but for ordinary people, actually wielding them properly was extremely difficult.
Take Yukino, for example. At her peak, she had once temporarily suppressed Sharon Holygrail, displaying strength on the level of a High-Class Devil.
And how long had it been since she reincarnated as a devil back then?
At most, just over a month.
In a little more than a month, Yukino went from an ordinary human to someone capable of unleashing High-Class Devil–level power. That wasn't just because of her outstanding talent, or because her demonic power after reincarnation rivaled that of a pureblood devil, it was also because of the Longinus Absolute Demise.
Longinus weapons existed to shatter the balance of power. They were artifacts that could allow ordinary humans to grow strong enough to rival gods and Maou. That was why Yukino could unleash such overwhelming strength.
And yet, what was the result?
She still nearly lost to Sharon.
At the time, she was simply too inexperienced. Her demonic power was only at a Mid-Class Devil level, and her physical stamina was even worse. She couldn't sustain the massive consumption demanded by a Longinus, ran out of steam midway through the fight, and was nearly caught in a trap Sharon had laid, almost getting purified on the spot.
This problem wasn't unique to Yukino.
Every Longinus wielder faced the same issue.
Shiina Mahiru, during the Old Maou Faction's invasion, had relied on the power of Incinerate Anthem to fight her way through countless obstacles. In the end, didn't she collapse in one of the later rooms due to exhaustion, failing to reach the Master's Chamber?
Even Hyoudou Issei, after reincarnating, he was considered weak even among Low-Class Devils. So despite possessing the Longinus Boosted Gear, which could theoretically increase power infinitely, once he pushed himself to the point of unleashing an attack comparable to a High-Class Devil, he hit a hard limit. After that single blow, he was completely drained and unable to continue fighting.
That alone said everything.
In short, Longinus weapons were undeniably powerful, but using them came at an enormous cost. One had to train hard enough to withstand their consumption and activate their abilities freely before even having a chance to truly shine.
But those rules simply didn't apply to Vali.
Because he possessed half the bloodline of a Maou, his innate demonic power was overwhelming. Not only could he freely use the abilities of Divine Dividing, he could even maintain Balance Breaker for an entire month straight. As for something as unreasonable as the Juggernaut Drive, he could forcibly wield it for several minutes purely through sheer demonic power.
That was beyond ridiculous.
Throughout history, not a single Red Dragon Emperor or White Dragon Emperor had ever managed something like that.
Balance Breaker itself had been reached by many past Red Dragon Emperors and White Dragon Emperors. But Juggernaut Drive was practically a curse. No one had ever been able to control it through their own power.
Whenever previous Dragon Emperors activated Juggernaut Drive, the outcome was almost always the same: total loss of control, rampaging until everything within their field of vision was destroyed.
And when they finally stopped, it meant their vitality had been completely drained by Juggernaut Drive. All that awaited them afterward was death.
Even Hyoudou Issei, the protagonist of the original story, had completely lost control after triggering an incomplete Juggernaut Drive, drastically shortening his lifespan. If Vali hadn't intervened, and if what he activated hadn't been incomplete, he would have continued rampaging until his life was fully burned away.
All of this made one thing clear.
Vali, who could forcibly use Juggernaut Drive for several minutes through sheer demonic power alone, was an existence that defied all common sense.
That was why he was the strongest White Dragon Emperor in history.
No exceptions.
With his current strength, even without Juggernaut Drive, just using Balance Breaker already put him firmly at Maou-Class combat power.
And how many Maou-Class fighters were there in the entire Underworld?
Setting aside the Four Great Maou, whose strength surpassed Maou-Class, as well as special existences like Grayfia, among the publicly known forces of the devil world, only a handful of devils possessed Maou-Class strength.
For example, a few of the top-ranked participants in the Rating Game. Or some ancient relics among the Seventy-Two Pillars families who had survived to the present day.
Other than them, there were no more.
But even if those devils possessed Maou-Class power equal to Vali's, could they really defeat him?
Don't forget, Vali was the host of Divine Dividing.
Once he was given the chance to activate his ability, the consequences were almost unimaginable.
Every ten seconds, an opponent's power could be halved once. And if he was in Balance Breaker, he could activate that ability at will. Theoretically speaking, the moment someone was touched by Vali, they would be reduced to nothing.
Even Leo didn't dare to let Vali get close enough to use his ability on him.
If that was the case for Leo, others would only be more cautious, more constrained.
So in Leo's view, Vali was already terrifyingly strong even without using Juggernaut Drive. If he added that on top, then in the entire Underworld, only the Four Great Maou could stand against him. Anyone else would simply be unreliable.
That was the sheer weight of White Dragon Emperor + Lucifer.
"So even you think the same way?"
Sirzechs looked conflicted.
He was extremely wary of Vali. After all, Vali's natural advantages were absurd, and he also shared an inextricable connection with Sirzechs' own house.
As a descendant of Lucifer, would he harbor hostility toward the current Maou who had seized the name of Lucifer?
That was still unknown.
And as the current White Dragon Emperor, he was also a sworn enemy of the servants under Sirzechs' sister.
It could be said that Vali's very existence was a threat, at least to Sirzechs and Rias.
If Sirzechs weren't so kind-hearted, and if another, more suspicious Maou were in his place, they might already be restless enough to think, "This child is terrifying. He cannot be allowed to live."
"Do you think Azazel had some ulterior motive when he brought that person into the Grigori?"
Sirzechs' real concern lay with the fallen angel governor.
There was no helping it. Just as mentioned before, in the eyes of many, Azazel was practically a villainous final boss. Every move he made seemed like it could be hiding some kind of scheme, making it impossible not to stay on guard.
Vali's identity was sensitive, his strength immense, his potential limitless. Such an existence falling into the hands of a 'villainous final boss' naturally made people uneasy.
"I don't think he has any strange intentions," Leo said, seeing Sirzechs starting to overthink things. "It was my first time meeting that fallen angel governor too, but the feeling he gave me… well, he does seem suspicious, very much like a schemer. Still, from what many people say, he's actually far more obsessed with researching Sacred Gears, and he sees himself more as a researcher."
"Besides, he was willing to sit down and talk with us. That alone suggests he doesn't want things to spiral out of control, right?"
"Whether that's genuine or just an act, having an opportunity where the three factions can truly sit down and talk calmly is rare. If we really don't want another war, then we should seize it, make our stance clear and let others hear our voice."
Sirzechs froze for a moment, then visibly relaxed.
"You're right. I was worrying too much," he said with a smile. "Things may not be as bad as we imagined. Opportunities like this are rare. We shouldn't give them up just because we're overly suspicious."
"Thank you for reminding me, Leo."
Faced with Sirzechs' gentle words, Leo simply shook his head.
"I just think that instead of worrying about that governor causing trouble, it'd be better to worry about other places," Leo said pointedly. "After all, the three factions currently share a tacit understanding: no one wants another war, one that could threaten the survival of entire races. So unless another madman like Kokabiel appears, the fallen angels are likely on the same page as us."
"On the other hand, there are some existences that have been lurking in the shadows all this time. They definitely won't just sit by and watch things develop this way."
"For example, the Old Maou Faction. And the Hero Faction."
Sirzechs stopped in his tracks, his expression turning grave once more.
He knew Leo wasn't speaking without reason.
The Old Maou Faction had always adhered to devil supremacy. Back then, it was precisely because they wanted to fight the angels and fallen angels to the bitter end that they drew the ire of the reformists, ultimately triggering the civil war.
Now, the Old Maou Faction harbored deep hatred toward the current devil society. There was no way they'd want to see the Underworld sit down peacefully with its long-standing enemies to discuss peace.
The Hero Faction was the same.
According to the intelligence Leo had provided, they viewed all non-human races as targets that must be defeated and exterminated, seeking to prove humanity's superiority. How could such a group tolerate peaceful talks between devils, angels, and fallen angels?
In the eyes of these people with ulterior motives, the tripartite talks weren't something that should proceed smoothly.
They were an opportunity.
An opportunity to gather the key figures of all three factions in one place, wipe them out in one fell swoop, and plunge everything into chaos.
Compared to the fallen angel governor, these were the ones who truly needed to be watched.
"…It seems that before the talks begin, there's still a lot we need to prepare for."
Sirzechs appeared to have formed some ideas of his own.
"As long as you're aware," Leo said, nodding in satisfaction after seeing that his words had sunk in.
The two of them then unfolded a magic circle in front of themselves and teleported away.
Their destination: the old school building of Kuoh Academy, the Occult Research Club.
At that moment, the night was far from over, and darkness still blanketed all of Kuoh Town.
Too many things had happened that night. Even ordinary residents had noticed strange disturbances, ranging from the clashes between Eligos' servants and the Cerberus pack, to the massive upheavals caused elsewhere.
Especially Leo's battle with the Cerberus King. A mountain had been set ablaze, and the area below reduced to ruins. Combined with the various anomalies appearing outside the town, Kuoh Town had been thrown into turmoil.
To prevent the unrest from spreading, the Underworld had already dispatched many people to handle the aftermath.
Some were there to repair the damaged terrain. Others were tasked with erasing the residents' memories, ensuring that everything that happened that night would be completely concealed.
A portion of them had also been sent to Kuoh Academy itself to carry out repairs. After all, the battles that took place there had been fierce, and the damage severe. If it wasn't fixed in time, tomorrow's students would be in utter chaos.
The outskirts of Kuoh Town also required attention. The impact of Leo and Vali's battle was even greater than what had occurred at the academy. Leaving it unattended would only spark public panic.
Thus, throughout the night, countless unknown devils arrived in Kuoh Town, diligently working to clean up the aftermath.
Meanwhile, the Occult Research Club room on the second floor of the old school building remained brightly lit.
Members of the Eligos servants, the Gremory servants, and the Sitri servants were all gathered there, listening to Sirzechs' announcement.
"…That's the situation. The three factions will soon hold a formal talk. As parties directly involved in this incident, you may all need to attend and provide a comprehensive explanation and report."
Sirzechs' words caused everyone present to exchange uneasy glances.
"A tripartite summit?" Sona Sitri adjusted her glasses, her expression serious. "I didn't expect things to escalate to this point."
The others looked just as uneasy.
The incident had been massive, but no one had expected the final outcome to be talks between the three factions, leaders sitting down for negotiations.
This was unprecedented.
"The three factions that have been enemies since ancient times… actually sitting down to negotiate?" Rias murmured softly.
"This has never happened before," Ravel said, visibly tense.
In contrast, Leo spoke calmly.
"Not exactly. While this is the first formal talk, the three factions have cooperated once before."
As he spoke, Leo turned his gaze toward someone in the room.
The others followed his gaze, realization dawning on their faces.
"W–Wait, what? Why is everyone looking at me?"
Standing in the corner, looking completely lost, Hyoudou Issei suddenly found himself at the center of attention and panicked.
Seeing the original protagonist, Leo couldn't help but smile.
"Because the thing residing inside your body is the very reason the three factions cooperated that one and only time."
That was what Leo said.