Izuku-117

(Inspired by Halo)

Legends persist that, in the past, before quirks had sprung into existence over a thousand years ago, humanity had not only achieved commercial space travel but had colonised the entirety of the Sol System, from Earth to the Galilean moons of Jupiter. However, something had happened that had reduced humanity to just their home world of Earth, and only now, with the reign of All Might and the age of heroes reaching their apex, has mankind finally been able to reach out to the moon and retake their colony there once more under the banner of the Colonial Hero Authority, a subsection of the United Nations Hero Command, or UNHC for short.

However, discontent is growing within hero society as people begin to rise up against the UNHC. Villainy, a majority of them operating under the banner of the United Villain Front, has been on the rise in the form of terrorism and piracy against trade spaceships that operate between Earth and the lunar colony of Reach, but are met by the UNHC with force. However, the UNHC's heavy-handed tactics in suppressing these villains results in the complete destruction of a city known as Far Isle, and, in the face of continued quirk discrimination, oppression at the hands of heroes, and corruption within hero ranks themselves, sparks a dozen more revolts and rebellions across the world, coming together to form a fully-fledged Insurrection against the UNHC. All Might becomes a major propaganda piece for the UNHC, and though while they openly condemn the usage of any military force in the wake of the heroes, the CHA authorises the creation of a military branch of the UNHC known as the Orbital Drop Shock Trooper regiment, or ODSTs for short, highly trained soldiers capable of dropping down from orbital ships onto insurrectionist forces, and they too soon become pubic figures in propaganda pieces for the UNHC.

Meanwhile, one scientist working for the black ops wing of the CHA, the Office of Naval Intelligence (or ONI for short), comes to the conclusion that in less than ten years, mankind will be thrown into civil war and hero society will be completely destroyed. To combat this, the scientist in question, Doctor Catherine Elizabeth Halsey, acquires funding for a project of her own: the Spartan-II program.

Soon enough, a hundred and fifty quirkless children around the ages of four and six, including one Izuku Midoriya, are selected and taken to the lunar colony of Reach to begin training into a new form of soldier that would be ready to fight and crush the Insurrection. They would spend the next ten years honing these children in the perfect soldiers, eventually culminating in their mission to capture the current leader of the Insurrectionists, defected CHA hero Watts, real name Robert Watts. After that, it's time for their genetic augmentations and modifications, of which only half of them, including Izuku, survive.

However, on their way to covertly claim their armour from the USJ satellite in synchronised orbit above U.A., the Spartan-IIs, temporarily led by Izuku Midoriya, full under attack as soon as they arrive, along with the visiting Class 1-A, by an unknown enemy.

Not the League of Villains, but a collection of mutants divided into separate breeds and species, who arrive on a spaceship that is far more advanced than anything that mankind have themselves.

They call themselves the Covenant, and they are the instrument of humanity's destruction.

Izuku-117 and the other Spartan-IIs are able to evacuate the U.A. students and cut off the space elevator connecting them to the ground below. However, one Spartan known as Yuga-034, is forced to stay behind as the remaining Spartans evac, and then detonates the entire station and sacrifices herself to kill the Covenant on the station and destroy the ship next to it.

Soon enough, the Covenant begin to arrive on Earth en masse, and the CHA finds themselves extremely flatfooted by this new enemy. The UNHC, however, quickly diverts its resources from the Insurrection to the Covenant as they begin to glass and destroy colony satellite after satellite. The UNHC quickly absorb the CHA into its own body, and many Insurrectionist and villain groups sign up with the UNHC to fight back against the Covenant, recognising the aliens as a much greater threat than anything that the UNHC themselves can muster.

However, not every Insurrectionist group would get the memo, and the MLA, Humarise, and League of Villains would reach out to the Covenant for an alliance.

The Covenant would feign agreement.

Meanwhile, ONI would see the devastation that the Covenant were reigning on Earth, and realise that if this pace was kept up, then even with All Might's help, mankind would be destroyed in less than several years. They instruct the UNHC to begin a mass militarisation across the planet, and begin a new programme of their own.

The Spartan-III program, aimed at created Spartans in higher numbers and lower costs, all in the name of slowing down the Covenant. The likes of Eri, Kota, Mahoro, and Katsuma are kidnapped by ONI and augmented and mutated into this new breed of super soldier.

Soon enough, the UNHC completely militarises and enters a state of total war against the Covenant, and find that while their space forces are vastly inferior to that of the Covenant, and that their heroes are barely on par with the Covenant ground forces themselves, their soldiers outclass the Covenant due to differing military ideologies and methods. The Covenant were, like the heroes, more warriors than soldiers, and acted accordingly. Additionally, almost all of the targets that the Covenant hit seem to be linked by the historical artifacts that had only recently been uncovered.

Meanwhile, the Covenant are suffering from their own internal strife as well. It is revealed that all the primary races within the Covenant (Grunt, Jackals, Hunters, Drones, Brutes, Prophets, and Elites) are all radically evolved humans, mutated by their own quirks and turned into new species. More than that, almost all of them have fallen into worship of the artifacts that they have uncovered on their worlds, all of them belonging to the interstellar humans who came before, whom they refer to as the Forerunners. On top of that, the Prophets have begun placing the violent and easily controllable Brutes in positions of military authority in their War of Annihilation against humanity, in contention with the noble Elites who have long since ruled over the Covenant's armed forces.

Back on Earth and its satellite colonies, Izuku-117 and his fellow Spartans continue to fight back against the Covenant, especially when they begin hitting sights such as U.A.'s Sports Festival and the city of Hosu, but with each passing battle, even with the help of the heroes, ODSTs, and even Spartan-IIIs such as the Headhunter pairs like Mahoro-B292 and Katsuma-B091, and Noble Team such as Eri-A259, Kota-A266, Samidare-A052, Tamashiro-A239, and Satsuki-B320, they were still losing Spartans with each battle, with barely anytime to mourn them before they were moved off to the next battle, leaving the remaining Spartans to become stoic and rather unemotive in order to protect themselves.

Soon enough, U.A's summer camp is attacked by the Covenant, who have begun to use Humarise, the League of Villains, and the MLA as proxies for their war on Earth. The summer camp is ravaged, many are slaughtered, and at the Battle of Kamino, the Covenant decide that all three of their proxies have outlived their usefulness and wipe them out, killing All Might in the process as well.

However, at the remains of the summer camp, ONI analysists uncover a strange artifact, and the Covenant freak out when they see the humans defiling a religious artifact of such reverence to them.

The Covenant attack the lunar colony of Reach en masse, and Izuku-117, now ranked as a master chief petty officer, and the remaining Spartans are pulled to defend their home. However, most of the Spartans die in the conflagration, and Izuku, now paired with an experimental A.I. made from the comatose Ochako's still living brain (after she was wounded and mutilated by the Covenant's forces during the Battle of Kamino), accidently activate the artifact recovered from the summer camp grounds...

And creating a massive portal that swallows Izuku, his new A.I., a large portion of Reach's UNHC personnel and Covenant invaders.

One that transports them to a massive ring floating in space.

A Halo.

Soon enough, war breaks out between the stranded UNHC and Covenant forces, the two factions trying to take control of the Halo ring and figure out how to get home as Izuku and his A.I. are whisked away by a strange machine known as the monitor, which refers to itself as Guilty Spark, monitor of Installation 04,, and identifies Izuku as a reclaimer of the Forerunner's legacy.

It informs him of a greater threat than the Covenant. One that has been accidently unleashed with the arrival of the UNHC and the Covenant.

A parasitic virus known as the Flood.

Soon, the Flood begin to run rampant across the ring, infecting both human and Covenant and seeking to find a way off the installation and infect the rest of the Sol System. Hoping to stop them, Izuku works with Guilty Spark to begin the activation sequence for the Halo ring. However, this is stopped by the A.I. of Ochako, who has infiltrated the Forerunner systems and reveals what the ring truly is:

Thousands of years ago, humanity hadn't just spread out beyond the Sol System, but across the entire universe, colonising entire galaxies and becoming a civilisation so advanced and so magnificent that it made them seem like gods. However, one day they came across a civilisation that was even more advanced than them, only known to them as the Precursors...

And so humanity wiped them out, down to the last.

However, the Precursors themselves would survive as dust, but that dust would soon mutate and become corrupted, becoming a monstrous parasite known as the Flood, which would infect almost all of humanity and force them to construct and fire and Halo rings, which wiped out not just the Flood, but their food as well. Humanity wiped out all life in the universe and reseeded it with new life, and left a special gene code in all future humans to activate and grant them the ability to command the Engineers, access the creations of the Forerunners, and reclaim their Mantle of Responsibility to the galaxy.

However, when this gene code activated within the Forerunners' descendants, it mutated in many of them to become quirks, their new powers, and thereby scrambling their DNA to be unable to activate Forerunner artifacts. It is only the quirkless, now a marginalised minority, who can access Forerunner technology, and allow humanity to reclaim the Mantle once more.

Realising that Guilty Sparks seeks to activate the Halo array and kill all life in the galaxy once more to destroy the Flood, Izuku and the A.I. Ochako turn on the Monitor and put forward a new plan: destroying Halo in its entirety and annihilating the Flood before they can get off to safety. Finding a crashed UNHC vessel on the ring's surface, the Spartan-II and his A.I. would fight through the hordes of Covenant, Flood, and Sentinels to ignite the core, then flee through a portal as the ring exploded, completely destroying the array and all the Flood on it...

Just as the portal deposited Izuku and his A.I. companion onto another Halo, one already occupied by the Covenant, just as a small army of UNHC personnel arrive through the same device found on Reach.

Meanwhile, within the Covenant, the tension between the Elites and the Brutes has only increased. The Prophets punish the Elite in charge of Installation 04's protection, marking him as the Arbiter, and send him off on a mission to eliminate a group of heretic defectors in a scientific survey site close to the destroyed installation. His mission is successful, but he is confronted by the Monitor of the destroyed ring, Guilty Spark, which tries to explain much of what it said to Izuku, but is taken away by the Chieftain of the entire Brute race, Tartarus.

Meanwhile, Izuku and the UNHC do their best to combat the Covenant on Installation 05, even managing to assassinate one of the Hierarchs of the Covenant. However, they soon find themselves at odds with both the Covenant and the Flood, as Izuku is kidnapped by a greater intelligence within the parasite, and the Arbiter, after witnessing the changing of the guard of the Prophet's protectors and chief commanders from the Elites to the Brutes, is sent down to cleanse the ring of the infestation and prevent the humans from reaching Halo's control room.

The Arbiter succeeds once more, and corrals the humans at the ring, especially a quirkless officer by the name of Melissa Shield. However, Tartarus quickly arrives and captures Melissa, before revealing to the Arbiter that his species has been ousted from the Covenant and branded for death, and is sent falling to the bowels of the Ring below...

Where he is captured and, along with Izuku, presented to the Gravemind, the central intelligence behind the Flood, and it is through the also captured Monitor of Installation 05, Penitent Tangent, that the Arbiter finally learns himself what the purpose of the rings are, and the truth behind the Forerunners.

As the Covenant purge Installation 05 of the Flood, the Gravemind sends both Izuku and the Arbiter away, the former to High Charity, where he chases down the last of the Hierarchs as the Elites and Brutes begin to kill each other and the entire Covenant falls into civil war. However, the entire structure is soon overrun by the Flood fleeing from Installation 05, and A.I. Ochako is forced to stay behind to try and keep the Flood contained while Izuku flees back to Earth on the Prophet of Truth's ship.

Meanwhile, the Arbiter is deposited back onto Installation 05, where he, alongside humans and Elite-friendly forces in a tenuous alliance, fight through hordes of Brutes and Covenant loyalists to reach the ring's control room, where they rescue the captive Melissa from the Brutes, stop the firing of Installation 05, and kill Tartarus in quick succession.

When Izuku arrives back on Earth, he finds a devastated world, a Covenant in civil war, and the UNHC and Elite-led factions of the Covenant Separatists aligned together to stop the Covenant Loyalists from breaching the portal device on Earth, having been moved from Reach on the moon to Japan, of which they are unable to stop them.

However, a Covenant ship infected by the Flood breaks through Earth's atmosphere and lands in Japan, forcing the Elites to glass the entire island nation. In the crashed ship, Izuku finds a message from A.I. Ochako, who tells him a horrifying truth about the Covenant.

The Prophet of Truth is actually All for One, and he wants to fire the Halo rings to leave himself as the last living thing left in the universe.

The remnants of the UNHC and the Covenant Separatists follow the Prophet and Brute forces through the portal, arriving at a massive floating structure in space known as the Ark. There, they do battle with the Covenant Loyalists and make their way to All for One himself, just as the Covenant's High Charity, completely infected by the Flood, crashes onto the Ark.

The Arbiter kills One for All, stopping the activation of the Halo rings, and the Flood begins to ravage all forces on the Ark in turn. In response, Izuku and the Arbiter, along with Guilty Spark, commission another Halo, a replacement for the destroyed Installation 04, to fire around the Ark, wiping out the Flood once and for all.

But first, Izuku must infiltrate High Charity, recover the badly traumatised A.I. Ochako, and destroy the entire structure behind him to get the activation index for the ring's firing mechanism.

Soon enough, Izuku and the Arbiter, A.I. Ochako and Guilty Spark make their way onto the new, unfinished Installation 08, but upon learning that a premature firing of the ring against the Flood on the half-made ring and Ark would destroy the installation, Guilty Spark turns on the trio and attempts to destroy them, only to be destroyed in turn as the ring begins its firing sequence.

The trio escape on the UNHC ship known as the Forward Unto Dawn, but it is cut in half by a collapsing Slipspace portal back to Earth as the ring fires and destroys itself, wiping out all traces of the Flood off the Ark and eliminating their threat forever.

The half of the ship that the Arbiter had taken shelter on lands on Earth and is recovered, and he and the surviving leaders of the UNHC sign a treaty that ends the Human-Covenant War, bringing their long struggle to a close.

In the aftermath of the war, humanity spends years rebuilding their home of Earth whilst taking advantage of their new knowledge of the Forerunner caches on their world and the various pieces of Covenant technology left behind to build new spacecraft to spread out into the solar system, eventually colonising the entirety of the Sol System in less than a year, with outposts set up as far out as Neptune and the asteroid belts around Saturn. Soon, the UNHC would grow to become the most powerful human faction in the system, eventually swallowing the CHA whole and turning themselves into the United Nations Space Command, or UNSC for short, discontinuing the usage of heroes and pushing the resources dedicated to heroics into their new military forces. Not only that, but a select few of these former heroes would be selected for their services during the war to become a new breed of Spartan, eventually becoming Spartan-IIIIs and numbering first in the dozens, and then in the hundreds.

However, not everyone would be content with this new piece. Not everyone within the various insurrectionist factions that had existed before and during the Human-Covenant War had been killed, and they begin rebuilding and stirring resentment against the UNSC. In particular, factions of the MLA, Humarise, and League of Villains would begin to grow once more, and other factions would begin to rise, made up entirely of former heroes who were marshalled out of service and feel resentment against the UNSC for phasing them out as a societal and military class.

And on top of that, errant whispers would circle around the Outer Colonies. Rumours that All for One was still alive, and was planning his return...

Meanwhile, the Arbiter would reform the various Covenant remnants and splinter cells under his command, most of them being Elite like him, into an organisation known as the Swords of Sanghelios, and takes them back to their home world of Sanghelios to begin rebuilding their culture in the wake of the revelation of the Covenant's lies.

However, not every Elite would be pleased by the truce with humanity and seek a continuation with the conflict, whilst others would still cling to their reverence of the Forerunners and see the Arbiter and the SOS as heretics. Soon enough, the Blooding Years would begin, a civil war that would last for many years as several Elite-led Covenant remnants, such as the Servants of the Abiding Truth and the Defenders of the Sanctum, and others led by the likes of Sali 'Nyon, Merg Vol, and Thars 'Sarov, would begin to wage their own campaigns of terror on both the SOS and the UNSC, whilst Jackal pirate clans constantly raided key targets of opportunity, from shipping lanes to cargo freighters to entire planetary outposts, and various Brute-led factions and remnants, such as the Keepers of the One Freedom, the Voice of Maardoth, and other Covenant loyalists and Brute raiders would attack both each other and others out of need for glory and blood in the name of their clans, most particularly the Elites, dragging the two species into a war just as destructive as the Blooding Years.

One Covenant remnant in particular would become a major threat to both the UNSC and the SOS. Operating out of the Sangheili colony of Hesduros, Jul Mdama's reborn Covenant, known by many as the Storm Covenant, would become a massive terrorist organisation and religious cult that would draw thousands of Elites, Jackals, Grunts, and Hunters to their call. Whilst not nearly as big as the Covenant that came before, they would be classified as the number one threat to both the SOS and the UNSC, as their fanaticism and zealotry would make them both extremely desperate and dangerous in their raids and terror attacks on various targets across known space.

In response to this threat, the UNSC would continue to grow more and more with power as they begin a cold war against not just the Storm Covenant, but all remaining Covenant remnant factions, eventually becoming so big and powerful as to dwarf them all. However, this would only continue to stir resentment against the UNSC from both human and Covenant factions, and the UNSC would slowly begin to grow too big for its own britches, becoming more bloated with each passing day as more and more heroes were phased out and began to take up arms against their former government. In particular the few surviving students of U.A., most notably Bakugo, who had been folded into the UNHC's ODST corps at the twilight of the war, grew angry and resentful of the annulment of the hero rankings and heroes in general, and, aside from the ones who allowed themselves to be turned into Spartan-IIIIs, with no purpose left in their lives with the heroes gone, they would begin to defect and go their own ways, some of them becoming the equivalent of wandering ronin across the Outer Colonies, fashion themselves as mercenaries, or join the various Insurrectionist movements growing across all of human space.

The threat of a human civil war had never gone away during the war. It had simply been tempered, not quelled completely. But now, it seemed to be nothing short of inevitable once more.

But in the darkness, away from the eyes of both the SOS and the UNSC, a banished legacy of the Covenant would begin to grow. Having been formed with the revelation of the Covenant's lies, and originally being comprised or nothing but Brutes, now this new faction would incorporate thousands upon thousands of former Covenant warriors, from Grunts to Jackals to Hunters to even Elites, becoming a brutalist mercenary faction of pirates and raiders under the charismatic leadership a Brute War Chief known as Atriox.

The Banished would begin to bide their time as they built up their strength. They would watch and wait as the UNSC began to bloat and poison itself whilst the SOS would grow more and more embroiled in their civil war. Soon enough, it would all come crushing down, and both mankind and the Elites would be thrown into a new war once more as the secrets of the Forerunners would begin to come to light...

And when they all fell to ruin, the Banished would rise, taking the secrets of the Forerunners for themselves and becoming the dominant power in the universe, where the treasures that they plundered and the lives that they took would be not for lies or servitude, but in the name of their own free will.

But somewhere far away, the severed half of Forward Unto Dawn would stay drifting in space, and Izuku-117 would shelter himself in the ship's experimental cryostasis, sleeping for many years as the universe evolved around him, all the while the A.I. version of Ochako would continue to watch over him as they drifted off to parts unknown...