『What? You're right… your exhaustion is far lower than projected. How is that possible? Using Ignis at full power should have taken an immense toll…』
As Ddraig puzzled over it, Ignis herself provided the answer.
『It's because the Oppaiser's energy acted as a buffer. Issei, you docked while you were in peak condition, right? That allowed the Oppaiser to shoulder the cost of the Longinus Raiser. In short—the power of breasts is supreme.』
「『...』」
Both Ddraig and I fell silent. Ddraig was likely struggling to process the logic, but me? I understood Ignis perfectly. I understood it all too well.
Alice, Rias… thank you. Thank you for the breasts. Thank you for so much breast energy. You two… are the best!
After a moment of profound gratitude for the power of "Oppai," I turned my gaze back toward the Trihexa, which had taken the Longinus Raiser head-on.
The beast was still there, but it had lost nearly a third of its body. Even the mighty Trihexa had sustained massive damage from Ignis's full power. Furthermore, the magic formulas etched into its skin had been wiped out, meaning it could no longer produce mass-produced dragons or clones.
However…
"Wh-what…?!"
A gasp of horror escaped my lips. The Trihexa was beginning to regenerate. Tentacle-like masses sprouted from the scorched cross-section of its flesh, rapidly rebuilding its body. In mere seconds, it had returned to its original form—magic formulas and all.
Ignis's voice turned grim. 『I see… it's just a guess, but Trihexa likely has a core hidden somewhere. Unless that's destroyed, it will regenerate eternally. Even if you fired another Longinus Raiser, it would probably adapt its defense. Not that you can fire another one in your current state anyway.』
"…Dammit!"
That was the last thing I wanted to hear. Even if I could shoot again, the odds of winning were plummeting.
The Trihexa's eyes locked onto me again, glowing with a sinister light. Having identified me as a threat, the evil aura radiating from it surged violently.
This is bad. I think I just made it angry. Either way, the situation was looking grim. The Trihexa opened its maw wide, gathering an unbelievable amount of energy. If that hit me, I was finished.
"Leave this to us, Issei-kun."
A third voice echoed from nowhere. Simultaneously, a barrage of high-density attacks rained down from the heavens, slamming into the Trihexa.
I recognized that aura.
"Sorry we're late. I shall join the fray as well."
"Yahoo! Issei-kun! Magical☆Leviathan has arrived to help!"
It was the Lucifer and Leviathan peerages, led by Sirzechs-san and Serafall-san! Two of the Four Great Maous who supported the Underworld were standing right here.
According to Tia, the Maous were supposed to be focused on defending the Underworld. Why were the two central figures here?
Sirzechs-san answered as if he'd read my mind.
"Do not worry. The Underworld only faced one split body of the Trihexa and its pawns. With Sairaorg, Tannin, and now Crom Cruach joining the defense, the situation is stable. Furthermore, Ajuka devised a magic formula to place a specialized barricade on the 'Gate.' It allows our forces to enter this world, but prevents the enemy from stepping foot into the Underworld. It is a temporary measure, but effective."
Crom Cruach was helping? Right, he had been staying with old man Tannin as a guest. I guess he was repaying the favor. And Ajuka-san was a genius as always—inventing a one-way barrier like that changed everything. It meant we could go on the offensive without worrying about our home.
Serafall-san gave a peace sign, looking delighted despite the situation.
"And you know what? A volunteer army has been organized among the citizens of the Underworld! they're helping with rear-line support for the main army. I was so moved I cried my eyes out!"
Seriously? The civilians were helping too? If the logistics were secured, the frontline soldiers would have much more breathing room. That explained why the tide had turned in the Underworld.
Sirzechs-san stepped forward.
"I heard from Azazel. The god beyond this point is waiting for you. And you intend to settle things with him. If that is the case, leave this place to us and go."
"That's right! Sirzechs-chan and I are Maous, after all. We have to work hard!"
The kind-faced Sirzechs-san and the high-tension Serafall-san both had the same look in their eyes—the look of unshakable resolve. No matter what I said, they wouldn't budge.
In that case, there was only one thing I could do.
"Sirzechs-san, Serafall-san… I'm going. But before I do, there's something I have to say to you both."
"?" They both tilted their heads in confusion.
"Our 'Sister-Talk.' We haven't done nearly enough of it yet. We're finishing it later, okay? Promise me."
At my words, the two of them beamed.
"Fufu, very well! I shall tell you even more about my dear Ria-tan!"
"And I'll show you my secret, treasured photo album of So-tan! So, Issei-kun, you have to come back! That's an official order from a Maou! ☆"
"You got it!"
Passing by the Trihexa, I finally reached it. The pitch-black tower at the center of the world.
As I approached, the massive doors at the base groaned open with a thunderous rumble. So, you're inviting me in…
The interior was surprisingly simple compared to the exterior—stone walls, floors, and pillars. Aside from a few magical engravings, it was devoid of ornament. However, the scale was vast; it was so wide I almost forgot I was inside a building.
"This feels… nostalgic," I muttered unconsciously as I flew through the halls.
I already knew why I felt that way.
After a short while, an altar appeared in the depths of the hall. At the center of the altar sat a throne, and upon it, a single shadow.
I landed before the altar and looked up at him.
"Kept you waiting?"
"No. I figured it was about time you arrived… Hero-kun."
The young man clad in robes of darkness—Asem, who had become a Demon King—offered a thin smile as he welcomed me.
-------------------------
If you enjoy this story, you can read 70+ advanced chapters on Patreon!
Webnovel will keep getting 1 new chapter every day but Patreon readers can stay far ahead.
Maybe it's not a big deal now… maybe it will be later.
[email protected]/Greyhounds
"And If you're enjoying it, drop a Power Stone for me!"