The Underworld. Devil territory.
A black vortex appeared in midair at some unknown point, spinning slowly.
It gave off no aura, no fluctuation whatsoever, as if "nothingness" itself had taken visible form. Never mind ordinary devils, even a Maou standing right next to it probably couldn't detect it without laying eyes on it directly.
Suddenly, several streaks of light shot out of the vortex, materializing into three figures of varying sizes.
"This is... the Underworld?"
Leo, twelve black demonic wings spread behind him, held Kanna's hand in his left and Stella's in his right. He looked down at the mountainous, river-threaded landscape below, studying it for a while before confirming where they were.
"Ophis was surprisingly thoughtful."
Leo figured the exit opening into the Underworld instead of elsewhere was deliberate on Ophis's part. Since he was a devil, she'd connected the portal to the Underworld.
"Too bad I'd rather go back to the human world right now."
The Dragon God's thoughtfulness had missed the mark. What Leo cared about most was the situation at Kuoh Academy's summit and whether his servants had escaped the Hero Faction's pocket dimension. He wasn't particularly eager to return to the Underworld.
"Well, being out at all is good enough."
Leo quickly stopped dwelling on it. Compared to the Dimensional Gap, the Underworld was familiar ground. He could use a magic circle to jump back to the human world. It just took time. Compared to being trapped in the Gap, that was nothing.
The priority was contacting Yukino and the others to check on their situation.
With that in mind, Leo let go of Stella's hand, raised his palm, and prepared to open a communication magic circle.
But before he could reach out to Yukino, someone else contacted him first.
"Leo! Are you back?! Where are you?!"
The voice that came through the magic circle, along with the projected image, belonged to none other than Sona.
The normally calm and rational heir to the Sitri house was speaking with an urgency that was completely out of character. A rare crack in her composure.
The obvious worry and relief were enough to make Leo smile.
"Yeah, I'm back. I'm fine for now." Leo's voice softened unconsciously as he spoke to Sona. "I'm in the Underworld. I'm out of danger, so don't worry."
"The Underworld?" Sona visibly relaxed, as if a weight had been lifted. "That's good."
"How are things on your end?" Leo asked immediately. "Is everyone okay?"
"More or less. At least no one died." Sona had already regained her composure. "That day, a dense fog that appeared to come from the Dimension Lost wielder filled the entire Kuoh Academy grounds. It forcibly transported you and all your servants away, but left us behind."
"After the fog cleared, we were attacked immediately."
Sona seemed to have guessed that Leo had been cut off from the outside world and was desperate for information.
So she gave him a concise rundown of what had happened that day, bringing him up to speed.
The situation was largely similar to the original story. While Leo and his servants were forcibly transported into the pocket dimension to fight the Hero Faction, the Old Maou Faction launched their own assault.
They attacked the school buildings, overwhelmed the guards the three factions had stationed at Kuoh Academy, and then directly assaulted the three factions' leaders. Their intent was clear: kill Sirzechs, Serafall, Azazel, and Michael right there.
To that end, the Old Maou Faction's leaders, the descendants of the original Maou, all took the field.
And the unexpected part wasn't just them. Someone who had been on their side had also joined the attack...
"Vali Lucifer. He'd secretly joined the Khaos Brigade and been recruited by the Old Maou Faction."
Sona's tone was heavy as she brought this up.
She also filled Leo in on the context before he could respond, in case he didn't already know.
"The Khaos Brigade is the underground alliance that the Old Maou Faction, Hero Faction, and other terrorist groups all belong to. This organization was established at some unknown point, recruiting dissidents and dangerous individuals from every major faction under the banner of the Infinite Dragon God. Without anyone realizing, it grew to a scale capable of influencing the entire world."
"Especially within the Devil, Angel, and Fallen Angel factions. Many who were dissatisfied with the status quo had secretly joined. People like Kokabiel, who wanted to reignite the war, were everywhere within it. Radicals and heretics from the Church had also joined."
"Before this, nobody had noticed the organization existed. Only the Fallen Angels' Governor had sensed something off, secretly sent people to investigate, and eventually discovered it."
"On our end, we only picked up on some clues after the Lafei Trix incident and started looking into it."
Sona paused, still clearly shaken. The idea that such a dangerous force had emerged without anyone knowing was terrifying.
Especially after learning that the organization's leader was none other than the Infinite Dragon God, Ophis. Not just Sona, even the leaders of the major factions had gone pale.
"But Sirzechs-sama and my sister... seemed to already know something. Even when Governor Azazel brought up the Infinite Dragon God and the Khaos Brigade, they weren't too surprised. Their expressions just turned somewhat grim."
Sona's observation skills had always been sharp. She'd noticed this at the time but hadn't mentioned it.
Now, recalling the situation, she brought it up in passing.
"What happened after that?" Leo asked, not telling Sona he already knew about the Khaos Brigade and Ophis, nor that Sirzechs had known in advance because Leo had deliberately tipped him off.
After the Lafei Trix incident, Leo had pointedly brought up the Ouroboros symbol in front of Sirzechs. If Sirzechs still couldn't figure out that the Old Maou Faction had the Infinite Dragon God's backing after a hint that obvious, he'd have no business being a Maou.
Given its connection to Ophis, Sirzechs couldn't possibly ignore the potential threat. He'd clearly conducted a deep investigation afterward, likely following the Infinite Dragon God thread until he, like Azazel, discovered the Khaos Brigade's existence.
After the three factions decided on the peace treaty, Sirzechs had actually intended to raise the matter. Unfortunately, the attack came before he could.
As for Vali defecting and joining the Khaos Brigade, not just Leo, even Azazel had probably seen it coming.
The Governor of the Fallen Angels was sharp. Vali was someone he'd personally raised, practically his own son. There was no way he hadn't noticed something off.
Even if he hadn't noticed anything specific, Azazel would have suspected Vali might do something, because he knew all too well what kind of person Vali was: a battle-obsessed warrior who craved nothing more than fighting the strong.
Peace? For most people, that was the dream. For Vali, it was a death sentence.
He didn't want peace. He wanted to fight. To face the strongest opponents and revel in combat.
So once the three factions decided on peace, putting an end to their conflicts and working toward a harmonious world, Vali naturally wouldn't want to stay.
Joining the Khaos Brigade, making enemies of the three factions and potentially every other mythological faction, was probably far more appealing to him.
Vali's betrayal and departure were entirely predictable. Leo didn't need to be surprised.
What he wanted to know was what happened afterward, and whether it matched what he knew.
"After that..."
Sona slowly recounted the events for Leo.
Unlike the original story, since the attackers were the Old Maou Faction and no other Khaos Brigade faction had moved against the three factions, Sirzechs and Serafall felt the devils should take responsibility for dealing with the Old Maou Faction themselves. So Azazel, Michael, and the others ended up as spectators and didn't intervene.
Vali had challenged Sirzechs, the strongest Maou, in the name of Lucifer. Meanwhile, the descendant of old Leviathan didn't waste a single word before consuming Ophis's Snake and attacking Serafall, the current Leviathan. The battle between old and new Maou had begun.
With those matchups set, the Gremory and Sitri peerages naturally couldn't stand by watching. They each engaged one of the remaining two old Maou descendants.
The Gremory peerage fought the descendant of old Beelzebub.
The Sitri peerage fought the descendant of old Asmodeus.
The results were brutal. Neither peerage was a match for their opponent. The Gremory peerage especially was in far worse shape than when they'd faced Kokabiel.
The descendant of old Beelzebub was the strongest leader of the Old Maou Faction. After receiving Ophis's Snake, his power rivaled that of the original Maou Beelzebub. A peerage that couldn't even beat a sub-Maou-Class Kokabiel had no business fighting someone like that.
Fortunately, Azazel provided support from the rear. His years of Sacred Gear research had produced several practical tools, including one that could force Issei into Balance Breaker without any cost. That let Issei unleash combat power surpassing anyone else in the Gremory peerage, barely holding the line.
Without that, the Gremory peerage would have been completely overwhelmed and wiped out by old Beelzebub's descendant.
The Sitri peerage was in dire straits too. Without Sona's quick thinking, they couldn't have stalled old Asmodeus's descendant at all.
In the end, Sirzechs settled things first. He crushed Vali with overwhelming force, so fast that Vali couldn't even activate Juggernaut Drive before going down. Then Sirzechs moved to reinforce the Gremory peerage, saving them from the brink.
Serafall proved herself equally worthy as one of the Underworld's strongest female devils. Her Super Maou-Class power was on full display. Old Leviathan's descendant, who'd only reached Maou-Class through Ophis's Snake, was no match for her whatsoever and was frozen solid on the spot.
After defeating old Leviathan's descendant, Serafall naturally rushed to save her little sister's peerage, easily defeating old Asmodeus's descendant as well.
By then, Sirzechs had similarly taken down old Beelzebub's descendant.
The results stunned everyone who witnessed them.
To the uninformed, the current Maou shouldn't have been able to match the old Maou descendants in bloodline or innate traits. Even if the current Maou were competent fighters, going up against old Maou bloodlines enhanced by Ophis's power, a draw would have been a good result. How could they have won so easily?
Not just ordinary observers. Even Azazel and Michael had thought the same.
They didn't have a thorough understanding of the current Maou's true strength. To beings from the ancient era who had fought the original Maou, the current Maou, who'd only existed for a few centuries, were practically children. How could they be well acquainted with their actual power?
Sirzechs especially had never entered his Destruction Form since the Devil Civil War. The details of that battle hadn't been leaked, so outsiders had no way of knowing that this "young devil" who'd taken the name Lucifer could actually rank among the world's top fighters, standing alongside chief gods and divine kings of other mythological factions.
Serafall, while not as strong as Sirzechs, was still Super Maou-Class, already surpassing the original Maou.
The current Maou were all monsters in disguise. Only a few centuries old, yet every single one of them had quietly grown to jaw-dropping levels. For old-timers like Azazel and Michael, who were still coasting on their ancient foundations, it was almost embarrassing.
In terms of raw power, the devil faction had already pulled far ahead of the other two factions. If the current Maou hadn't all been easygoing, content with peace, and unconcerned with power and status, the devils would have been dominating the angels and fallen angels already.
And so, this crisis of the Old Maou Faction's collective assault was never really in question as long as Sirzechs and Serafall were there.