[I'll be honest, even to the moment of posting, I'm a little bit uncertain about this, but... This is kinda my vision for how I wanted Nil's character arc to progress, and I want to stick to that. Don't worry, you guys will all get your conclusions unimpeded, once this is done.]
The nuclear blast obliterates what seems to be Amakros' body.
"... Yeah..."
Nil breathes in and out, empowering his guns yet again and pointing them at the man coated in black flames.
"... You know, it's weird. You seemed like a big, noble guy, and you managed to get everyone on your side until you started pulling the global corruption thing. With how persuasive you were... Why didn't you just rule over humanity normally? You definitely could have managed it."
"... Frankly, I don't believe in humanity. I've seen them fail, over and over and over again... And... it's funny that I brought Amakros of all people out as a last ditch effort. Because he was the embodiment of what I hated... Arrogance, blind faith in one's kind because they can believe in themselves... I knew demons were volatile, but I also knew they had their own set of rules that I had authority over. Even if I understood their flaws... Demons were something I could believe in. Do you believe in humanity, as it is?"
"..."
Nil goes silent for a bit... Thinking about everything, and looking around him.
"What can I say, times have changed. I've changed, ever since I was the person you exposed me to be. I've kinda had to believe in them... And it hasn't really failed me so far."
"You... have to? You just went along with what you were told, refusing to carve your own path or seek change?"
He chuckles a bit...
"Then I've already won."
With that, a chill comes over everyone.
Suddenly, the laws of the world shift.
THE WORK
... Cain now comes to the horrifying realization... That even if he did a great deal of damage, the only thing he truly destroyed... was the Doppleganger. Some shadows that represent Amakros still lingered, even if those shadows are twitching against Zephyr's control.
"... To shift the laws of the universe is quite the accomplishment, I cannot deny... it can even bend time to grant one's wishes, if used wisely."
They feel it too, Zephyr's corruption accelerating over the entire planet, sweeping across the moon as they barely have time to even react.
"..."
Nil takes it all in... The very world coming undone as they know it...
Then again. There's just one thing he stuffed far up his sleeve... Far enough that he hoped to never have to bring it out.
"You know, you have a fair point. All this time, I've mostly just been trying to get back on my feet. Rolling with stuff and hoping I don't let the earth get so wrecked that Ichika would consider me a failure and make sure to make my departure permanent this time."
Nil looks around again, even allowing a smile to creep upon his face.
"But... You guys? In the face of this..."
"Yeah, I'm going to believe in humanity. Because I have a lot of good friends here that made the journey worth it. Through all the random BS and things going left and right... And, I got to star in one of the shows I passed the time with, so, win win."
"But I guess all good things have to come to an end.
Nil starts glowing silver again, then Red, then he puts his finger up to his head.
"... My status isn't nearly as far off as you might have thought it was, looking at me. It's been building up, just out of reach... But right now, I don't care what happens to me. I'm going to reach for it."
Jeahbongchim... Beyond reasonability.
A moment of stillness washes over everyone. Then, suddenly, the corruption is entirely removed, being replaced by a starry, cosmic landscape as far as the eye can see.
"... You...?"
Zephyr coughs out, confused as anyone else at this turn of events, staring at Nil.
Nil, who's body had seemingly become the epicenter for this landscape. His body shining brightly, though it still retains the general shape he's been known for this whole time.
"... Your concept of demon overrode Ilya and Ichika's capabilities... But I am the source of their powers, just as I told you. As you can see, it turns out that I edge them out just enough when I'm like this. And speaking of Ichika... I'm fulfilling her promise. I'm sending you back home."
Zephyr... Can't help but crumble to the ground in defeat. They all pulled out their absolute in desperation... rest is his only option.
"Retcon."
Zephyr disappears, whisked back to his homeland. And as the wave of power washes over everyone, the earth around them starts to be restored. Humanity is no longer cut to a fraction of it's overall population, nor are they forced onto the moonbase in a chaotic situation. Nor are any of the buildings destroyed... Cities irradiated... or buildings crumbled, even. And thus, everyone just finds themselves at a castle in good old, every day Transylvania.
... Then Nil feels the pulsing within his being.
The stars within and without him dissipate, as he coughs out a great deal of blood, collapsing onto the ground.