I've been screaming for the past few minutes.
I can't help it. It feels like my insides are being churned and boiled at the same time. The world is twisting in my eyes, and I can see the blackness slowly creeping around my vision. But I can't let myself faint, and I can only clench my fists and scream as I fight against my body's basic instincts.
Akeno is kneeling behind me, her palm pressed harshly onto my unclothed back. Her teeth are grit, and she's barely holding back her tears as she tries her best to guide the pure Mana rampaging through my insides. I can almost feel her overflowing self-loathing over it, her hatred over the pain she's causing me. I would've turned to comfort her if I could.
But I can't, and both of us can only suffer in our own minds.
It took Akeno a month before she was satisfied with the Mana Crystal she'd been growing. Once she did, we went to our summer home in Kyoto, and we prepared ourselves for my awakening.
It's an unpleasant experience all around. I had to consume the Mana Crystal whole. No mixing it with water, no crushing it before putting it into my mouth. I just had to chomp down on it, crunch it as quickly as I could, swallow it, and brace myself for the inevitable pain.
And I knew it'd be painful.
I just didn't expect it to be this excruciating.
In truth, I already have experienced a pain of this level before. It's when I broke through my first 'threshold' all those years ago. A stinging, melting pain that very nearly knocked me out. I can remember it now that I'm here. But I suppose I must've just…forgotten about it before.
At the least, I know for certain that this is all working. All the pure Mana I just ingested is being guided along by Akeno's hand, and my own dormant Mana is slowly waking up.
It's unfortunate, really. Had I been younger, my Mana would've had a much easier time waking up. But now, even if I'm barely a teenager, my body is that of a young adult. My physiology is stubbornly trying to keep everything stable. My body's not as rigid as other's—Primal Energy helps loosen that hold—but it's still terribly stubborn.
I'd been lucky when it came to Divine Energy. The Eyes of God acted as an easy conduit to allow absorption.
Mana doesn't have such a foothold in my body. And so it takes nearly an hour of mind-numbing pain for my body to finally get the memo. A 'gate' inside me crashes open, and my Mana wakes to find my body filled with barely restrained Mana of the highest purity.
And my Mana goes insane.
Like a child drunk on candy, my Mana begins consuming all the pure Mana rampaging through my veins. It eats and eats and eats, and the more it does the more my control grows over the typhoon of Mana inside my body.
That newly-converted Mana then joins in the conquest, eating up more and more of the pure Mana that first came from Akeno's Mana Crystal. The increase in speed is exponential, and the growing feeling of power swirling inside me is almost terrifying to bear.
In just a minute, all that Mana has been absorbed.
And the roof promptly explodes as all that latent energy explodes upward, rising towards the sky as an enormous pillar of light.
Thankfully, I had the foresight to place an 'Isolation' barrier over the entire place, just in case something like this happens. Even then, the 'Isolation' barrier just barely holds against the onslaught of power contained in that pillar.
Eventually, the magic calms. The pillar of light fades, and the sky trembles as the 'Isolation' barrier shatters just seconds after the whole debacle ends.
In the wake of all that, I find myself lying on the floor, my breaths warm and heavy as I stare at the open skies. Akeno is just a few rooms away, having been blasted through several walls due to the explosion.
I can't help but smile wryly. "That's a first." I mutter, idly glancing around at all the devastation I wrought. The ceiling had suffered the worst, but the rest of the place hadn't gotten off cleanly either. Walls have fallen down, the floors are torn apart, and most of the plants grown in the inner gardens are uprooted.
I pushed my hand towards the sky, and the world glows gold as the Eyes of God comes to life. Equations and calculations swirl into my head, connecting into one another to form an array of numbers. My Mana notices this, and suddenly all those numbers floating in my head disappear, and heat begins gathering at my fingertips.
I take a breath, and at my command, a beam of plasma shoots off into the sky, disappearing into the clouds.
Just like that, I've just performed one of Akeno's favored attacks. The formation of a ball of plasma, sent flying forward at intense speeds to melt through anything in its path. A seemingly simple spell that requires an insane amount of calculation.
Despite all that, only a single thought runs through my head.
"Slow." I say, frowning as I stare at my fingers. "It's really slow."
Casting that spell had taken me a few seconds. Impressive by most standards, but it's inadequate for me. I could've done a lot more in those few seconds if I used my other powers.
It's not an issue about my mental capabilities. I can calculate fast enough.
The issue lies in my body. Most of my powers are instinctual; they just need to hear my 'intent' and follow through. Magic is different, needing me to run entire calculations, then wait for my Mana to respond, before finally having the spell be cast out into the world.
This is Magic's main drawback, I suppose. Variety and efficiency, but requiring more time.
Battle Mages like Akeno are special cases. She's able to call for her lightning and her plasma with hardly any wait. With the only caveat being that she's trained her body to cast those specific spells for years until her Mana can instinctually respond. And even then, it's only for those two spells.
Then again, I'm not planning to use Magic to fight in the first place. I mean, I'll eventually get to that someday, but for now?
Magic will be involved in a much more important project.
"Having fun?" I hear, and I turn to see Akeno stagger through the wall she'd been flung through. Her hair is caked in dust and splinters, and there are tears all across her dress.
"A little." I say. She huffs as she lays just beside me. "Getting used to how hot my insides feel. I feel like I'm about to explode at any moment."
"You just did." She says.
I laugh. "...I have nothing to say to that."
We lapse into a short silence. I glance at her. She's smiling slightly, and there's a palpable sense of relief in her eyes. She's promised to do this for years now, and it's finally been done. But the smile on her face is a little stiff despite it all.
I stare for a moment, before I say, "It's not your fault."
"Mm." She hums and says nothing more.
I sigh, and simply intertwine her hand in mine. She moves just a little closer, enough for our shoulders to bump, and her smile turns just a little lighter. We lie there for quite a while, silently staring at the open skies.
"People are panicking." Akeno then says, her smile curving to a small grin.
A wry smile lifts my lips. "I mean, our house did just blow up." I say. "They probably think we got attacked or something." I huff. "They're probably scared their Great Lady is hurt or whatever."
She scoffs at the nickname. "Hmph. My popularity is but a grain of sand compared to yours, Seicho-sama."
I grin at her. "Your fans will go to war if they hear that."
She grins back. "So will yours."
I hate how we can joke like this. I mean, I don't…mind the admiration I get from the Youkai. But fans? Really? Why…?
As I said, I don't mind. It's just-, I've gotten one too many marriage proposals in my mailbox, and even a number of letters just straight up asking me to impregnate someone. My answer has always been a polite but succinct "No."
Even then, they still come. It just doesn't end.
But hey, at least Yasaka and Nurarihyon got a few laughs from it all.
…
"Issei."
"Yeah?"
She turns to me, and there's a soft smile on her lips. "I'm really happy." She says. "I've never felt so happy. It almost hurts." She continues, and she gently turns and hugs me. "Being here, having my own family, being able to do what I want-" She nestles into my shoulder. "It almost feels like a dream."
I smile. "Hey, come on now." I turn to her, and I give her cheek a gentle squeeze. "What's this all of a sudden?"
She shakes her head. "Nothing. Just felt like saying it." She leans closer, and kisses me on the lips. "I love you." She says after.
And hearing those words, what else can I say but, "I love you too."
As we kiss once more, I raise my hand towards the sky, and cast a fireball towards the sky. It flies up, before it explodes, spreading across the blue skies like a firework.
Many will be confused about it for the next few days, before it'll be forgotten, swept away in the lieu of the quickly advancing progress occurring in Kyoto. Our summer home will be rebuilt in just days, and we'll share a quick laugh about it all someday.
But for now, this moment we share, adorned by the falling firework above,
It'll be our anthem for the future. The end of an arc of our story, and the beginning of another. It'll be a promise we share. Our promise to continue growing and living and loving despite the absurdity of this cruel universe.
It'll be our binding vow.
Finally, the end of the third arc. And with it, the beginning of DxD canon. There was supposed to be more, since there's still a third volume of Slash/Dog, but, uh-, Satanael's kinda dead. So we'll be hopping straight to canon.