Hello!

Welcome to my crossover for Assassin's Creed and D Gray man~ This started as self indulgence to have Altaïr and Allen meet, and then I just fell in love with it.

A few things to know: Allen has a canon au backstory and the main fact to know is that he's 19; I have my own headcanons for Nea (and for Crown Clown) which will show; this is set in Altaïr's era, not long after Al Mualim's death, and it remains possible characters of later eras might appear, but not a certainty; these is a very high chance this will be Altaïr/Allen (it might remain implicit, or it might be clearly stated and shown); this story is meant to give enough to be read whether you know only one fandom or both (but doesn't explain everything right away); I have a few plot twist and events more or less planned.

For the most part, I do simply follow where this goes, each chapter has helped me figure out the one(s) that follow, and planted those ideas for plot and event I mentionned. I have some ideas of where this is going (it is likely the crossing over will eventually be both way), but I'm not rushing toward it either; and so this might also be kind of slice of life. Kind of.

Also, very important: I have chapters in advance (12 after this prologue) and I will be posting once a week (every wednesday). I might "pause" posting, if I want to give myself room to breathe, so keep an eye on my ANs for any mention of me pausing (and well generally, do keep an eye on ANs as I'll put warning and stuff like that).

Enjoy~!

Full summary because FFnet a butt compared to AO3: Two worlds which would have been fated to never meet; except... Allen Walker is cornered, scared, desperate; Nea interfers, but he gave no direction to the Ark bare Take him away from here and Allen floats in the void between spaces. The Apple cannot resist the call of giving knowledge, a location; and Allen lands in Altaïr's room.
No one could guess the impact this meeting would have on both lives, and on both worlds.

Assassin's Light

Prologue

Three months, so many days spent moving, always a step ahead but sometimes barely.

Three months on the run, hiding and avoiding all those that knew him, for many reassons.

Three months he had managed to remain out of Apocryphos' grasp.

And right here and now, he failed. He did not manage to get away in time.

Allen barely had time to process the sudden spike of worry and anger from Crown Clown's before a hand grabbed his neck, pressing him into the wall, his left arm sprouting even more feathers as he met the wild gaze of the independent Innocence.

"Finally. You have been a bad boy, Allen." Apocryphos purred, one hand still around his neck, ignoring the right hand that tried to pull it off. "But have no fear, I will soon rid you of this Noah that taints you."

And fear he felt, when the sensation he never wanted to feel again started, when he felt the invasion of Apocryphos' mind in his own, when he sensed Crown's agitation as the guardian of the Heart forced his Innocence to accept the fusion.

He was powerless, no match for Innocence, not when his own could not disobey.

He found himself hoping for Tyki and Road to show again, for the Noahs to know again that he was in danger. Who else but them could match Apocryphos?

Rage suddenly flared into his mind, covering the fear, the pain, even Apocryphos faltered at it.

"How dare you!"

A deep voice snarled, but not Allen, and yet he felt himself speak, just like he saw the purple energy that sparked all around his right arm. But Allen could sense it, how the Noah within him could not keep it up.

It was a split second decision. A split second of Apocryphos' surprise. A split second of control.

Nea smacked Apocryphos' hands off, and then, even as those hands reached for the body again, Nea sent all his remaining energy into a single command for the Ark, Crown Clown's own powers flowing from its own desire to protect their precious host.

Take Allen away from here!

Bright light flashed behind Allen, Apocryphos' eyes widened in despaired anger, fingers brushed clothes, but too late.

Allen fell into the Ark's gate, the whiteness shattering around already, breaking fully when all of him went through it.

And he fell still, into whiteness, as if he was floating down, a feeling like exhaustion creeping into his body and mind.

The Ark had no direction, no landing point.

Allen had barely any consciousness, mind still reeling from the attempted fusion.

Nea was falling dormant.

Crown Clown flared once last time, pleading, into the nothingness of the void between space, for somewhere to land.

Space, dimensions, worlds; a theory that the Isu knew about. Their calculations, their knowledge, however, never found a proof, or at least, only of the possible futures of their own world; but the theory had remained.

And the Apple, full of knowledge, was ready to offer it to those that sought it, lure them to it.

A pulse awakened the Apple, the golden sphere starting to lit up, but without witness.

Let me give you a location. Let me give you all you need.

Let me guide you. Let me keep you.

The Apple reached out, the light even brighter.

And then the Apple recoiled, growing dim again.

It had been rejected, violently.

"My master is not yours to command!"

Yet, it felt the knowledge had been taken.

It had been enough, no matter the intent, no matter if the last strength of Crown Clown was spent rejecting the intrusion.

The Ark had a location.

And Crown Clown grew dormant itself, energy drained to open the gate once more.

Light flashed again the room, but not from the Apple this time.

A white, diamond-like shape rose from the floor, a body falling from it, landing while the whiteness shattered and vanished.

The young man caught himself on a desk, clinging to consciousness by a small thread, silver eyes dazed, feathers slowly drifting back into his left arm until it was back its normal inactive state. A golden orb on the desk, and one fluttering in front of his face, his mind processed the flying one must be Timcanpy, the worried noises confirming it.

Allen offered a weak smile, and then, darkness claimed him, his last feeling being the golem returning into his pocket.

All Altaïr had wanted was to rest, to lay down and relax after another day spent discussing with Malik the changes he wanted to bring. He had yet to regain the trust of all assassins, but his unwillingness to punish them, especially Abbas, had earned him back some of those that rebelled already.

Abbas was another matter, unwilling it seemed to let go of his suspicions, of his hate. At least, while Malik would never lose the sharp comments, Altaïr knew their bond was healing. Malik could see him as the man he was becoming, while still ready to call him out, but never in blind hate. And the new Mentor knew he needed that, not that he would easily admit it.

But still, it had been a long day, and Altaïr wanted his rest. For once, he did not even feel like sitting by the Apple, questionning whether or not to use it. The knowledge he knew he could gain still tempted him, but the memory of Al Mualim were still too fresh. He could not risk it, not when he was only starting to rebuild the Order.

So really, the last thing he needed was an intruder in his own room.

Yet, Altaïr could not miss the sound that came from inside just as he reached for the door, a thump on the ground.

The assassin threw his door open, moving inside with his hidden blade ready in quick steps.

He stopped short when his amber eyes landed on the form on the floor in front of his desk, half covered by the strange, beige coat they wore. Altaïr frowned, careful as he approached, gaze flickering to the Apple.

It had not been moved at all. Had it reacted before, or had they collapsed before they could touch it?

Altaïr knelt beside the form, taking into the white hairs, like snow, then he grabbed their shoulder, pushing to roll on the side. He had half expected the youthful face, the body had not been one of an old man, however, what caught his attention was the red… brand? Tattoo? On his face. All red, it started above his left eye as a pentragram, then a line down his eye and his cheek, another line crossing it as the cheek.

The young man, who Altaïr estimated to be in his late teens, at most twenty, also had a too pale skin, the traces of exhaustion in his traits, and the assassin felt the shivers under his hand. Even passed out, the younger's face twitched, forming a pained expression, betraying whatever had caused him to faint was still affecting him.

His clothes were also strange, Altaïr could see now a white tunic and a black vest, a red ribbon around his neck, as well as dark pants and brown boots, hands covered by white gloves. It did not quite look like attires worn in the Holy Land, but Altaïr wasn't sure he had seen foreigners wear anything like this either.

He shifted his hand, checking the pulse, which at least seemed to be steady, if a bit weaker. A second look over the male's body confirmed he could not see blood. Still, he rolled the stranger on his back, checking for hidden blades but finding none. Neither did he find any physical injury, which left Altaïr thinking exhaustion seemed to be the likely cause.

A touch of the forehead confirmed what he felt when he checked the pulse, the young man had a small fever.

Altaïr sighed, rubbing his temple. He just wanted to rest, this was too confusing. Besides, he would not be able to get answers for now, would he?

So he picked up the young man, one arm at his shoulders and the other under his knees, carrying him to his bed. Malik would probably have complaints tomorrow, but Altaïr did not feel like taking the time and energy to get the strange young man to a cell, to have to explain.

Not when he felt the smallest pang at the idea, and not when he could not help the way his eyes took into those exhausted, slightly pained traits again.

Altaïr had seen many bad men, many innocents, he had seen men with bad actions and good intents.

None ever felt this innocent to his eyes, more than all the people in towns, more than just someone to stray his blade from. None had ever truly brought him a sense of protectiveness.

Altaïr stared down as he deposited the young man in his bed, watching as the frame relaxed, the traits softened. Innocent, he looked so innocent, yet so… troubled. The assassin recalled about the fever, and moved to get a watered cloth, feeling his lips twitch at the corner as a small sigh left the young man once it was deposited on his forehead.

Tomorrow, he would gain answers. Tonight, he would let the young man rest, and do that himself.

He felt like sleeping in a pile of pillows tonight after all, right where he could see the night sky out of the window, and where he could also keep an eye on his bed, but not too close.

To be continued...