Attack on Titan x Male Reader : New Allies

War for Zeta Halo

Hello everyone, just to preface this, I'm not stopping Marley's Spy, I'm just dividing my time into what I want to write, and at the moment, this is what I'm enjoying doing.
If you couldn't tell, this is an AoT and Halo crossover, and it's not going to be another dimension or reality, just another planet deep in unexplored space that happens to be where AoT takes place.
I hope you enjoy it.

Having an eidetic memory was as much a blessing as it was a curse for Y/N. He could remember everything he saw, heard or read, and while people would think he was exaggerating when he told them, he really wasn't. It was freakish how much information was stored in his brain, and it also helped that he was a genius, being described as one of the greatest minds alive.

When he was seven years old, he had memorised all the mathematical equations on how to make a functioning slip-space drive after seeing them leaked online, of course he couldn't build one on his own, but it had fascinated him for years, and as time passed, he began to add and alter the equations on paper and sent them to the UNSC.

That was when he was thirteen, well into the human-covenant war that humanity was very obviously losing, he didn't know why he did it, he just hoped that these alterations would make a difference and help humanity in the war.

When he was fourteen, the covenant arrived at his home world, Earth, and while they only landed in east Africa, it was a terrifying experience for anyone living anywhere on Earth at the time. Half of Africa was glassed and a portal was opened above the city of Voy, with the covenant going through and the alliance of the Elites and Humans following, winning the war through the portal.

He joined the Office of Naval Intelligence when he was seventeen, three years after the war had ended, where he spent three years designing faster slip-space engines for ONI ships, he even designed faster archer missles and even faster rockets to be put on the WMD's that ONI were in possession of, and while he definitely wasn't an engineer, maths did not lie to him.

Now he had met many people who were somewhat jealous of how fast he had risen up the ladder at ONI, some would even say that he had done something or pulled favours in order to get into his position, but the truth was that he was just extraordinarily smart and had a knack for maths.

He had been lucky enough to be flown out to Australia to ONI's headquarters a couple of times, he even got to meet Admiral Serin Osman, the head of ONI, and to his surprise, she knew who he was and the great work he had done for humanity in the first couple years he had been a part of ONI.

One of the questions he had asked her was why they had allowed someone so young to work on some of their top secret programmes, and her answer was simple enough. She told him that humanity had paid the price before for letting talented scientists linger as interns and assistants for too long. She believed that all talent and genius should be put to work, no matter how young or inexperienced they were.

It was in her opinion that in order for humanity to not be caught out again by another growing threat, they had no time to dawdle after such a bloody and brutal war, having lost a huge chunk of their population as a species, it was in their best interests as a race to become as strong as they could as fast as they could, and if that meant bringing young but talented people into top secret military programmes, then so be it.

However, when she told him about the improved and expanded Spartan-IIII Programme, along with the fact that there was new generation three Spartan armour in development, he could tell she was hinting towards him being a candidate, otherwise why would she be telling him these things?

He told her he had never held a gun in his life, let alone shot at something, it wasn't something he was interested in at all, he was a mathematician, not a soldier. She told him that he could be the smartest Spartan to ever exist, but it still didn't convince him, so he went back to designing and improving the various weapons that ONI has in its arsenal.