Disclaimer: I don't own Halo or Mass Effect franchise
Author's notes: Hello folks! This is a new Halo - Mass Effect crossover story I am writing from scratch. I have abandoned the old "Mirrored Fates" fanfic story. This is a new reimagination of the crossover with no alternate universe bullshit! This all happens in the same Milkyway galaxy, but with an interesting take which I hope you all will like.
The reason I abandoned Mirrored fates is that it is the first fanfic I started writing back in 2016 based on inspiration from many other stories written by CreamofWheat, Freedom guard. There were lots of errors, lots of mishaps, lots of cringe stuff which I had no experience in correcting or handling them, especially in handling the characters in the story. But now I started to play ME legendary edition and all Halo games again which gave me a new vigor to start something new from an old idea.
With that being said, I hope to get your support in continuing this new storyline of Halo ME crossover. Cheers all and lets start over!
Chapter 1: Prologue - In the Distant Past...
500 million years ago, the Precursors seeded many lifeforms in the Milkyway to test which species is worthy to uphold the Mantle of Responsibility. Out of them all, Humanity, Forerunners and the SanShyuum emerged as the technologically most advanced species at Tier-1. Humanity and SanShyuum formed an alliance on Charum Hakkor. Humans and Forerunners emerged as the biggest military force in the galaxy and also become bitter rivals. Humans-SanShyuum alliance included a Tier-2 coalition of aliens called the Covenant who became resourceful allies. The members of the covenant included Sanghelli, Unggoy, Kig-yar, Jiralhanae and M'galekgolo.
Humanity accidentally unleashed the flood, an unknown virulent parasite upon the galaxy. In an attempt to stall the pandemic, Humans invaded forerunner space which started the Human-Forerunner wars. Both species suffered significant losses with humanity fighting the flood simultaneously on another front. Human military forces under Lord of Admirals Terrance Hood, Admiral Thomas Lasky confronted the flood while the Naval Special Warfare under Spartan-II Commander John-117 confronted both the flood and the Forerunner forces led by a ruthless leader named 'Shadow of Sundered Star' aka the Didact, to buy enough time. Meanwhile, the Forerunner builders gathered intel on the existence of a flood hivemind that's been controlling and coordinating the flood forces. This conflict went on for many centuries.
Amidst the chaos, a new and unknown enemy codenamed the 'Reapers' entered the galaxy and attacked every civilization on sight to harvest them. Seeing the emergence of this new threat, the Forerunners and Humanity set aside their differences and along with the SanShyuum and the Covenant together fought the Reaper forces. The Reaper ships were weak and were easily defeated, but war with the flood was taking much of a toll on them. Some human scientists theorized that since the flood showed signs of heightened intellect with enough biomass, the flood could have created the Reaper forces as additional weapon or tool to defeat them. But there was no proof to back that up.
The SanShyuum scientists worked separately to find the origin of the Reapers, but their research was cut short when the flood started to recede away mysteriously and soon shortly the Reapers did the same.
This sudden peace was unsettling for the 4 factions. The galaxy was scouted along the rim for the possible return of the flood or those mysterious Reapers. A century later, the Reapers returned in full force. But they were not alone, the Reapers vessels looked different, they were all carrying flood biomass, the original harvested lifeforms infected by the parasite. Also strange machines looking like tuning forks, started to pop out of nowhere across the galaxy. All of them had a glowing active core. The Reapers used them to enter deep into the galaxy than the last time. None of the races had the time to analyze them except the intel that it helps these squid like ships with a different form of faster than light travel.
Unlike the previous fight, this time, the reapers were prepared to face the galactic superpowers with enhanced weapons and defenses. Already having exhausted the military resources, the humans, forerunners, Sanshyuum and the Covenant stood no chance against the flood controlled Reapers. Humans had to use blitzkrieg strategy while the forerunners used slipspace reconciliation to clog the Reapers movement in space and time. But this strategy failed when the Flood controlled Reapers were able to bypass it using Neural physics based super-luminal travel. None of the races have seen that technology in use before. This lack of knowledge led to the serious disadvantage. In the final years of the war, Didact and John-117 discovered that a Keymind was coordinating these Reapers, using them as a means to consume life on the galaxy and then do the same on the other galaxies too. But no one were able to physically locate the all powerful flood hive. The SanShyuum concluded that the hive could be present outside the galaxy safely while coordinating the machines to do the dirty work. Even if that was the case, The Keymind was powerful enough to mutate space and time on a galactic scale from the outskirts, even manipulating slipspace to its advantage and were able to send tendrils of exotic energy that broke ships in half effortlessly.
Forerunner scientists built a contender class ancilla named Offensive Bias to coordinate the remaining Forerunner fleet along the galactic themas to counter the flood fleet. While the Humans built a powerful sentient AI named Cortana (CTN04-529) who would be paired with John-117 to fight and weaken the critical Reaper strongholds for 50 years using non-traditional strategies. Cortana's solutions would keep the Reapers at bay long enough for the Humans and their allies are evacuated to safety.
With the war moving nowhere towards the winning direction, Forerunners decided to catalog all the genetic samples for repopulation, then build Halo arrays, artificial ring worlds spanning 10,000 kms in diameter, resembling a bangle. These huge weapons will be used to purge all the life which would wipe the flood and every other lifeforms. This would also stop the Reapers from harvesting the life forms, since they too will die from Halo's pulse because of the collective consciousness it possess from harvesting intelligent lifeforms.
Human astro engineers constructed a planet, a shield world which hosted a dyson sphere of 500 million kms diameter within a time dilated pocket dimension to move the surviving and intact Human, SanShyuum, Forerunners and Covenant military vessels, the survivors from other primitive and space faring civilizations. They will be protected from the Halo's destructive effect.
After 5 centuries of conflict, the Halos were fired which purged the flood and every life form in the galaxy. Every Reaper vessel in the Milkyway was destroyed thus bringing the war to a bitter end. The apex species would admit their defeat, believing their own hubris was part of it and the internal conflicts weakened them and had them unprepared for the coming storm.
When the dust finally settled down, Cortana placed the key people who participated in the wars in a temporal stasis pods within a facility in the Dyson sphere. Offensive Bias initiated the reintroduction protocol to send the final survivors using keyships back into their home worlds where they would live out their lives and die and from their ashes, new species would rise and take their place continuing the natural cycle of life and death.
But till the very end, Humans, Forerunners, SanShyuum and the Covenant couldn't find the truth about the origins of the Reapers, none of their technologies existed earlier for them to uncover. They also don't know about their creators. But in the later stages of the war, the Librarian, leader of the lifeworker discovered the truth behind the flood parasite. It horrified her so much so that she never disclosed that information to anyone.
John-117, before going into temporal hibernation, asked Cortana to setup a warning beacon about the Reapers as he believed this new and unknown enemy might possibly be still out there in the intergalactic void, waiting to gather their numbers and come back for harvesting the life. He also believed that the Keymind might still be alive since it was not present in the galaxy during the war and the Halo's effect didn't go beyond the edges. This beacon will hopefully be found by the future civilizations to help them prepare for the Reaper threat. Offensive bias, after completing the reintroduction protocols, fragmented its matrix into 3 parts and went into hibernation mode. Cortana did the same hoping to be awakened in future if the galaxy needs their help.
But unknown to them, the Reapers were not defeated entirely. While they lost a significant number of ships, they still had enough numbers to invade and harvest the galaxy again. During the war, the Reapers broadcasted a failsafe signal to the Citadel which would reach the station no matter where its kept hidden. This signal made the mass relays come out of their hiding in a cascade effect which then helped them to enter deep into Milkyway.
The Reapers secretly intercepted the warning beacon sent by Cortana destroyed it through quantum decoherence, so none of the future civilizations knew about it and the whole plan to prepare the future species for the Reaper threat became useless.
But why the Reapers do this, harvesting life? Who created those machines? The relation between them and the Flood? and why the mass relays and citadel were hidden for 20 million years and who hid them and why?...Only the Reapers know the answers to that...and they will be back!
480 million years later...
The galaxy is once again flourished with life. Several species like Asari, Salarians, Turians, Volus, Elcor, Batarians, Krogans, Hanar, Quarians, Vorcha, Yahg, Drell etc. took the galactic stage.
In the year 2148, a sect of human colonists unearthed Prothean archives on Mars, an extinct species, which every race in the galaxy believes to be the most advanced civilization that ruled the galaxy 50,000 years ago. With the knowledge obtained, humanity discovered the mass relays and the element zero. This strange element gave rise to a phenomenon which the galaxy calls it as the 'Mass Effect'. They excelled in use of this strange material for telekinesis which they term it as 'biotics' and faster than light travel for ships in short time leading to efficient colonization of exoplanets. Every species in the galaxy believes that the mass relays and the citadel were feat of Prothean engineering and the credits to all the galactic civilization's advancements are owed to them.
Humanity soon became the galactic council's favorite much to the dismay of many other species and has been pushing to become the 4th member of the council with the Asari, Salarian and Turian as the existing members. Every civilization is striving towards greatness with order and regulations to keep them in line.
But none of them know what is awaiting them in the future, completely oblivious to the approaching cyclone of dark fate.
Year: 2183 AD, May 25th
SSV Normandy, Upper Earth Orbit
Commander Eric Shepard is a spacer, who spent his life only on the ships. His parents were Systems Alliance soldiers, the military conglomerate that represents the human exploratory and military group. Shepard is a great combat soldier and a good biotic. He single handedly held the entire batarian invader fleet on the human colony Elysium till reinforcements arrived, the battle came to be know as the 'Skyllian blitz'. He was the reason the civilians were safely evacuated and the colony stood in one piece. He became Alliance's decorated war hero. His popularity reached the edges of the galaxy.
Now that popularity is the very reason he's been selected for a mission.
"What about Shepard? He's a spacer, spent his life on ships. This mission shouldn't be a problem for him" a male baritone voice spoke. It was Captain Anderson.
"But is it enough to win this fight?" another grumpy tone spoke. It was Councilor Udina.
"Shepard held an entire pirate fleet all by himself on Elysium. He is the reason the planet's intact. I say there's no one better than him for this mission" a deep militaristic tone spoke. It was Alliance Admiral Hackett.
"Courage and bravery can't win wars, Hackett" Udina said.
"Maybe, maybe he is not the right soldier we need, but he is the right soldier for this job right now" Hackett said.
"Commander Shepard, you presence in the bridge has been requested" a voice over the room's comm spoke.
Shepard who was gazing at the Earth through the glass window proceed to exit his room to go to the bridge.
Author's notes: This is just the prologue. It will start with Mass Effect 1st game and through the finale. This story will have many plot changes to suit the crossover. Hope you enjoy this. I will be writing a few more chapters on this before I continue the others. You will have the fan favorite characters from Halo and ME.