Disclaimer: I don't own the Digimon Franchise or To Aru Majutsu no Index. I wrote this solely for fun.
The speed of descent increased.
Kamijou Touma ran with everything he had within the flying fortress called the "Star of Bethlehem."
At the shore of the Arctic Ocean, at that threshold between land and sea Kamijou had forcibly destroyed the large ascent spiritual items in order to distort the fortress's trajectory of descent. He focused on nothing but running in order to oppose the archangel Gabriel.
There was something odd on the surface of the earth. Some kind of small form was approaching at high speed. Kamijou saw the white snow torn up along the path of whoever it was that was soaring along at low altitude with tremendous speed. The snow was not simply being blown away. All the snow within a few hundred meters...no, within a few kilometers of "her" was being absorbed.
A thick, long line was being drawn along that white land as the archangel approached. No one could stop her from advancing. There seemed to be human forms firing light that appeared to be magic, but the archangel paid them no heed. She merely passed through and the professional magicians were blown away.
The archangel passed the shore and made it to the Arctic Ocean. At the same time the "Star of Bethlehem" fell straight down from above and hit the archangel.
With a great roar the archangel and the giant fortress fell into the ocean. Inside the sinking fortress Kamijou used everything he had to head further and further down. Unable to stand up to the great pressure, walls and pillars within the fortress started to break one after another. The freezing seawater flowed in but Kamijou paid it no heed. He focused on nothing but heading lower...heading deeper. The fortress fell below sea level.
There was no longer any illumination. But...
There was a single point of light in the vast darkness. The peaceful light was blue and deep. It was reminiscent of moonlight.
Kamijou Touma clenched his right fist with all of his strength. His opponent had noticed him. The light in their eyes clashed within the darkness before the real clash. The mere human boy who was overflowing with a tremendous killer intent continued forward without stopping to the very end.
A lot had happened on his way there.
It had all started at the point where he had lost his memories. He had continued forward after lying to a certain girl in order to not sadden her.
He had fought an alchemist to rescue a girl who had special blood.
He had fought the strongest Esper in order to rescue the Third Level 5 and her Sisters.
A fight to the death had unfolded with a traitor of a classmate in a beach hut.
A lot had happened on August 31st.
He had stood up to a real golem in order to save his friend who was an aggregation of AIM diffusion fields.
He had picked a fight with the largest denomination of the Christian Church in order to save a nun who claimed to have deciphered the Book of the Law.
There had been an incident related to an underclassman of the girl from Tokiwadai Middle School.
During the Daihaseisai he had protected Academy City from the threat of the "Croce di Pietro" while it had gotten the coordinating committee member and his other classmates wrapped up in it all.
In Chioggia of Italy he had assaulted an ice fleet in order to save a girl who had once been his enemy.
On September 30th he had clashed with a woman from God's Right Seat in order to save his friend who had been completely changed.
He had enjoyed delicious sukiyaki with his classmates and then had fought Skill-Out in order to save the mother of the girl from Tokiwadai Middle School.
In Avignon of France he had fought God's Right Seat over the C-Document.
With the help of the Amakusa Church he had fought a powerful Saint in Academy City's underground district.
In London, he had stopped the coup d'Ă©tat led by the second princess.
And now...
'It's been so long.'
Not all of the things that had happened along the way had been enjoyable. He had hurt others and been hurt by others again and again and again. It was all a cycle of those two things.
But Kamijou Touma was still able to run. He knew those actions had saved quite a few people. And so he was able to head straight forward to face his greatest enemy yet, an archangel.
'It's true that this world may be destroyed one day. Even planets have a lifespan and I know it will be swallowed up by the expanding sun even before that is reached. And the odds of all life being wiped from the face of the earth before even that happens may be rather high.'
Kamijou thought as he charged forward with his clenched fist.
'But it does not have to have such a tragic end. There's nothing wrong with fighting to stop this.'
With a great crash, the two forms clashed at the middle point.
The archangel let out an unearthly, wordless scream as it focused the power it was able to recover and fired a giant beam of ice and reflecting ice. But...it wasn't enough. It lost too much and didn't recover enough.
The boy's right hand pushed the beam away and kept running in the tiny opening created between the attack and the ground. He kept running until he was right in front of the archangel.
Ice rose up to skewer him from all sides. The boy swung his right hand to shatter the ice, clearing a passage large enough to fit him and hitting the archangel at the same time.
Gabriel screamed.
Space and Time broke apart as "she" was forcefully returned back to "her" plane of origin. A tear formed where "she" stood, a black abyss engulfing the archangel, the surroundings...
And the boy. Kamijou Touma had the time to say only one thing before falling into darkness so ancient it doesn't even have a name.
"Fukou Da!"
At the same time, the giant Star of Bethlehem was crushed and destroyed as it had received the brunt of the shock from the fall.
The Digital World.
A plane of existence separated from the real world, brought into existence with the activation of the "Atanasoff–Berry Computer", the first computer, which laid the basic foundations of this world. Subsequently the first patented computer, ENIAC, was activated and proceeded to build upon those foundations, shaping the Digital World.
This is a world made of Data, not Atoms.
In the lowest layer of the Digital World, which resembles a desert plain, space warped into a tunnel that spat out a body before fading. The body, which despite the term used wasn't dead at all, belonged to a spiky haired boy wearing the tattered winter school uniform and a blue jacket.
The boy just laid there, unconscious, but if one were to look closer he could see strange movements that resembled colorless sparks surrounding his right hand.
Many balls of light converged from all directions and started hovering around the boy. Each ball contained a fairy-like creature, and each one was eying the boy with curiosity.
The creatures seemed to converse for a while before they started spinning and dance in the air, power of some sort condensing above the boy.
However, before they could do anything there was a sharp 'SNAP!' like sound coming from the boy's right hand. With a sound akin to shattering glass the accumulation of power was erased, along with some of the fairy-like creatures.
The remaining ones cried and fled away as the area surrounding the boy started flickering and breaking, almost like the strings of existence that made it were coming apart.
And then, as if the events of the day weren't enough...
A strange something started taking shape.
IT was awake.
Elation. Once again the Seal was broken and IT was able to come outside. IT thought this was finally the chance IT was waiting for.
But the Host was strong. So strong that it managed to stop IT before IT could defeat the enemy in front of IT.
Frustration. Why couldn't IT be allowed to act as IT pleased?
Reality disappeared. Nothing and Everything. Then a new place.
Confusion. IT didn't recognized the place. It was unfamiliar. The Seal too couldn't decide what to do and started cracking.
IT took the chance to prod outside. IT felt new presences, new rules of a reality that clearly wasn't the one from where the Host originated from.
Curiosity. Something was trying to do something to the Host, to...draw forth and give a shape to the Host's dreams? Intriguing.
The thoughts of IT were interrupted as the Seal decided this new reality didn't respect the Directive and started erasing it, along with the pieces of IT still outside.
Frustration. Then, Inspiration. The power to shape dreams, IT understood it. So why don't use it? It would allow for a part of IT to exist outside, unencumbered by the Seal. In time, the new part of IT may even manage to free IT fully.
With ITS remaining strength IT gathered ITSELF, copied the new power and fuse IT with it, adding data of the Seal and the Host to prevent the Seal from erasing the new part of IT. The new part will be separated from the consciousness of IT, but IT left enough of IT inside to ensure the new part will perform its role.
The Seal closed. IT smiled.
Satisfaction.
"Uurgh..." Moaning in discomfort Kamijou Touma opened his eyes. "What happened...Right! I defeated the angel! I think..." He pushed himself up into a sitting position and looked around. "A desert..? But I was near the Artic. How did I end up here?"
"You are awake." A monotonous, almost mechanical voice said behind the boy. Touma turned to look at the speaker, only to blink in surprise.
The owner of the voice, who was seated on a rock, looked as far as proportion went like a boy a little shorter than Touma. However, that was were similarities ended: his body was clad in a tight black bodysuit, with smooth red armor around his chest and crotch and spikes on his shoulders. His right forearm was encased in a thick looking red gauntlet, while the left forearm only had a bracer of the same color that left the hand free. On his feet he wore futuristic red and black boots.
But it was his face the most interesting element: he looked human, but his blue eyes, very similar to Touma's own, were too large and bright for a human; there weren't emotions in them, it was like staring into the eyes of a robot. The rest of his face, beside the mouth and cheeks, was hidden under a mask with red spikes on the sides and a large, blue oval like decoration that covered most of his head. Touma spotted fluttering, short blond hair behind it.
Also, unless he was seeing things the boy had a tail. And it moved like it was real!
No, Touma realized with a startle, he wasn't looking at a human being.
"Who are you? Are you a Tenshi (Angel)?" He asked, thinking of the angel he defeated and Kazakiri Hyouka.
The boy slowly shook his head. "I'm Undemon. I'm a Digimon."
Touma blinked. "Okay...Undemon, what is a Digimon? And..." Touma glanced around at the unfamiliar landscape, before looking up.
And witnessing not the sun or a clouds covered sky, but a pulsing globe made of numbers and light, with vast columns of pink energy reaching down like immense skyscrapers.
Kamijou Touma's reaction was understandable.
"WHERE THE HELL AM I NOW?!"
Undemon's reply was smooth and concise. "The Digital World."
Back on Earth, inside the district of Shibuya, Director Yamaki received an urgency call from Hypnos's headquarters regarding the sudden appearance of an unidentified anomaly in the Net.