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War of the Old Ones by Ian the Mechanic reviews
In forgotten ages past, two near eldritch forces vied for the very life essence of the Galaxy. Unknown to the young races, that war is still ongoing. how can the UNSC, the Citadel Council or the Covenant hope to stand against such forces, when they are still embroiled in their own petty squabbling? How could they hope to survive the War of the Old Ones?
Crossover - Mass Effect & Halo - Rated: M - English - Sci-Fi/Horror - Chapters: 25 - Words: 136,914 - Reviews: 145 - Favs: 296 - Follows: 443 - Updated: 8h - Published: 2/21/2022
Digimon War Game S2 by riven-del reviews
The Halo has been destroyed, but the Covenant have a new objective: Earth. Cassandra will have her work cut out for her as she helps the Pillar of Autumn's crew stall the enemy and more Tamers with crests show up.
Crossover - Digimon & Halo - Rated: T - English - Adventure/Sci-Fi - Chapters: 11 - Words: 13,406 - Reviews: 5 - Favs: 7 - Follows: 7 - Updated: 16h - Published: 9/2/2022 - OC, Herissmon, Master Chief/John-117, Fred-104
The Iron Cross by Lighting wolf knight reviews
Scattered, in a world where their emperor never existed... The Ultramarines have but one purpose... Protect humanity and act among them. Rated T for violence, death, and profanity. Read next chapter Author Notes for important news.
Crossover - Warhammer & Halo - Rated: T - English - Adventure/Romance - Chapters: 31 - Words: 106,516 - Reviews: 76 - Favs: 157 - Follows: 199 - Updated: 16h - Published: 7/15 - Space Marines, OC, Arbiter, Linda-058
Halo Galactic Wars: RE-IMAGINED by Crimson Soldat reviews
During the Battles of Zeta Halo, the Master Chief happens across a new site drastically different from the installation it resides on. Without any warning, he is violently sucked into a new war in a Galaxy Far, Far, Away. The following event will shake both universes and their respective peoples. And new secrets, thought lost to time, will be uncovered. co-written by F35B.
Crossover - Star Wars & Halo - Rated: T - English - Sci-Fi/Adventure - Chapters: 3 - Words: 14,010 - Reviews: 18 - Favs: 107 - Follows: 147 - Updated: 18h - Published: 7/14 - Anakin Skywalker, Obi-Wan K., Ahsoka T., Master Chief/John-117
ARES:The Gods of War by Johnnieboy11 reviews
Mankind's Greatest Hero has finished his mission once more. Saving Earth from the Didact and his weapon of mass-recruitment, the Composer, the Master Chief and his AI companion, Cortana, find themselves mysteriously transported to a strange variation of Earth, where machines rule the surface and mankind hides below. The SPARTAN and those that join will fight to Reclaim the world...
Crossover - Halo & Goddess of Victory: Nikke - Rated: T - English - Adventure/Sci-Fi - Chapters: 13 - Words: 47,790 - Reviews: 155 - Favs: 359 - Follows: 485 - Updated: 11/6 - Published: 11/29/2022 - Master Chief/John-117, Cortana, Commander, Rapi
Book 1: Wolves by Believer218 reviews
The Academy became the home of Spartan training after the loss of Laconia Station. Kept hidden for decades, it has the potential to tip the balance in favor of the UNSC. But secrets lurk beneath the facility, and they are about to be unleashed. Join the Lone Wolves as they embark on an adventure that could change more than one universe. The first adventure in the Lost Wolves Saga.
Crossover - Halo & Avatar: Last Airbender - Rated: T - English - Fantasy/Adventure - Chapters: 14 - Words: 84,973 - Reviews: 4 - Favs: 9 - Follows: 10 - Updated: 11/6 - Published: 6/27 - H. Dinh, OC, Aang, Katara
The Reclaimer of Mandalore by UNSC indomitable reviews
Having been awoken by his faithful companion. The Master Chief and Cortana find themselves in an unknown galaxy. Knowing the only way to survive is to remain under the radar. But in a galaxy gripped by war, such a thing was never going to be easy. As the Chief try's to up hold the status quo in the ever changing world of Mandalore, as the galaxy slowly torn apart around them.
Crossover - Star Wars & Halo - Rated: T - English - Sci-Fi - Chapters: 20 - Words: 121,141 - Reviews: 433 - Favs: 1,228 - Follows: 1,627 - Updated: 11/5 - Published: 11/25/2020 - OC, Master Chief/John-117, Cortana
Galactic Conflicts: Tales of First Contact by TheDoctor1998 reviews
Humanity and its allies have stood strong after the Great War with the Covenant. Follow the Systems Alliance as it goes through a first contact nearly as disastrous as the one that lead to the Great War.
Crossover - Halo & Mass Effect - Rated: M - English - Sci-Fi - Chapters: 4 - Words: 18,922 - Reviews: 62 - Favs: 173 - Follows: 237 - Updated: 11/5 - Published: 2/6
Halo: From Spartan to Seran by CommanderAuri reviews
What was originally set to be a smash and grab mission goes completely sideways. A haphazard escape through teleporter on the shield world Requiem's surface sends Spartan Commander Rachel Auri flying head over heels onto foreign soil with hostile contacts right on her tail. Follow her story as she tries to survive a planet that is constantly attempting to kill off it inhabitants.
Crossover - Halo & Gears of War - Rated: K - English - Sci-Fi/Adventure - Chapters: 7 - Words: 56,578 - Reviews: 21 - Favs: 35 - Follows: 45 - Updated: 11/2 - Published: 11/9/2022 - Marcus F., Dominic S., A. Cole, D. Baird
The Rook by Twisted Fate MK 2 reviews
On the way down to New Mombasa, Rookie falls into the Slipspace Rupture and ends up crashing down on Menae, high above Palaven, right in the midst of the Reaper War. From there, the war itself will shift and the fighting persists, but who knows what an ODST will add to the mix. (Redo of an older story)
Crossover - Halo & Mass Effect - Rated: M - English - Adventure - Chapters: 12 - Words: 41,629 - Reviews: 97 - Favs: 406 - Follows: 609 - Updated: 11/1 - Published: 7/8/2022 - Rookie, Shepard
New Era II by martinantab reviews
The war has ended and UNSC/UEG can finally start with rebuilding. Former Covenant races created new alliance to prevent another big war. Everybody thought that they can live peacefully, but few years later UNSC Gargantua has discovered mysterious object in the Orion's arm and no one is sure, if everything will be the same again.
Crossover - Halo & Mass Effect - Rated: M - English - Adventure/Humor - Chapters: 2 - Words: 8,078 - Reviews: 13 - Favs: 57 - Follows: 86 - Updated: 11/1 - Published: 10/28 - Master Chief/John-117, T. Lasky, Councilor Tevos, Councilor Valern
Many hands make light work by Polluxsashes reviews
A normal twenty-first century human mind stuck inside a Huragok, a Forerunner biobot, gets punted straight into the worst place anyone could ever be: Warhammer 40k. What is he to do but what he is made for? Beware all who call this horrid universe home, you will be 'halped'. First story on this site, updates every month. I have up to chapter 12 already written.
Crossover - Warhammer & Halo - Rated: M - English - Sci-Fi - Chapters: 12 - Words: 24,920 - Reviews: 110 - Favs: 364 - Follows: 498 - Updated: 11/1 - Published: 4/27
Halo: Doctor Who by TimeTraveller-1900
A series of one-shots chronicling the life of Doctor Who, a Time Lord from the planet Gallifrey, who is forced to flee his world after years of travelling the stars and trying and failing to make a better world, before becoming stranded during the Human-Covenant war.
Crossover - Doctor Who & Halo - Rated: M - English - Adventure/Sci-Fi - Chapters: 4 - Words: 4,352 - Favs: 5 - Follows: 9 - Updated: 10/31 - Published: 10/25 - 1st Doctor, 2nd Doctor, Martha J., C. Halsey
The First Men in Space by TimeTraveller-1900
A series of one-shots set in the 1964 movie, The First Men in the Moon, spanning decades as humanity moves out into the universe, fighting off Martians, and alien invaders, and encountering foes in other solar systems before discovering the Covenant.
Crossover - Misc. Movies & Halo - Rated: M - English - Horror/Sci-Fi - Chapters: 5 - Words: 7,191 - Favs: 3 - Follows: 7 - Updated: 10/31 - Published: 10/24
The Sins of our Fathers by MarkerMagnum reviews
Unknown to the Citadel Council, the Human-Covenant war nears its vicious end. Miranda Keyes is seconds too slow. Delta Halo fires, leaving UNSC space as a lifeless snapshot in time. The Citadel must morn the loss of a civilization they never knew.
Crossover - Halo & Mass Effect - Rated: T - English - Drama/Sci-Fi - Chapters: 10 - Words: 97,151 - Reviews: 434 - Favs: 1,216 - Follows: 1,658 - Updated: 10/30 - Published: 2/11 - Cortana, Councilor Valern, Councilor Tevos, Councilor Sparatus
Buzzard Buccaneer Radio by General Rage reviews
Boz the Buzzard hosts this pirate radio station, beaming out music to the Normandy, Fallen Serpent, Crusty Chorka and Ascendant Justice non-stop. BBR has only one mission, to keep Rock n Roll alive in the dark void of outer space. A companion story to "Remnants" that shows what happens while Shepard is off playing hero. Part of the Wormhole Chronicles Saga.
Crossover - Halo & Mass Effect - Rated: M - English - Humor/Sci-Fi - Chapters: 11 - Words: 84,796 - Reviews: 97 - Favs: 97 - Follows: 111 - Updated: 10/29 - Published: 9/21/2016 - OC
Project Atlas by Masso 2010 reviews
The Spartans are trained to be unthinking, unflinching and unmoving in the face of the impossible. Project Atlas is so much more, when humanity looks up into the sky they can see Hope, Justice, Reverence. When those that seek to hurt humanity look up into the sky, they see the warrior, the monster, the demon. To those who seek the destruction of humanity, he is the Cataclysm.
Crossover - Superman & Halo - Rated: M - English - Adventure/Sci-Fi - Chapters: 22 - Words: 164,862 - Reviews: 201 - Favs: 439 - Follows: 516 - Updated: 10/29 - Published: 4/17/2022 - Clark K./Kal-El/Superman, Master Chief/John-117
Horizon War:Tales of the UNSC-Citizen Federation War by Johnnieboy11 reviews
A chance encounter with Forerunner Technology leads the UNSC to discover a two-way portal which leads into a Universe so similar, yet ever so different from their own. First contact with said Universe's humanity, however, goes awfully wrong, sparking the greatest war since the Human-Covenant War. These are the tales of those who fought in it.
Crossover - Halo & Starship Troopers - Rated: M - English - Adventure/Sci-Fi - Chapters: 15 - Words: 55,690 - Reviews: 167 - Favs: 223 - Follows: 296 - Updated: 10/29 - Published: 6/13 - [J. Rico, Dizzy F.] C. Halsey, T. Lasky
Harry Potter got trained by Driver1985 reviews
On the night Harry would have been dropped off by his Aunt, Dumbledore had someone else in mind. What if Harry was taken in by other strong people and they even decided to train him? Trained to be a Warrior by Wolves and the UNSC, he will change the world. OP, smart, trained Harry, small harem double cross with Witcher and Halo
Crossover - Harry Potter & Halo - Rated: M - English - Fantasy/Sci-Fi - Chapters: 86 - Words: 431,952 - Reviews: 357 - Favs: 760 - Follows: 893 - Updated: 10/28 - Published: 9/30/2021 - [Harry P., Hermione G., Daphne G.] Master Chief/John-117
Remnants by General Rage reviews
From Halo's ashes, a mismatched Alliance is born. UNSC soldiers now serve alongside both Batarian deserters and shifty Jackal Space Pirates. Now Shepard and Master Chief have to keep these strange bedfellows from killing one another before they can stop an emergent new threat to the galaxy. The Next Swashbuckling Chapter of the Wormhole Chronicles.
Crossover - Halo & Mass Effect - Rated: M - English - Adventure/Sci-Fi - Chapters: 41 - Words: 863,235 - Reviews: 826 - Favs: 481 - Follows: 552 - Updated: 10/28 - Published: 4/22/2016 - Master Chief/John-117, Cortana, Tali'Zorah, Shepard
The Son of the wolf by Lighting wolf knight reviews
After the failed Hersey, the gods exile the broken Sons of Horus to another land... One where they may find redemption and a home. Rated T for violence, death, and profanity. Non chaotic/remorseful Horus.
Crossover - Warhammer & Halo - Rated: T - English - Chapters: 4 - Words: 7,335 - Reviews: 2 - Favs: 20 - Follows: 27 - Updated: 10/28 - Published: 10/15
Star Wars: Odyssey of the Infinity by IX404 reviews
During a routine safety test, the Slipstream Space Drive of the Infinity malfunctions, catapulting them into unknown space. Little do Lasky and the members of the Infinity know is that they will soon change the fate of a far away galaxy. (Undergoing Chapter-by-Chapter Rewrites. Chapters 1-3 rewritten. Chapter 4 rewrites ongoing.)
Crossover - Star Wars & Halo - Rated: T - English - Sci-Fi/Drama - Chapters: 32 - Words: 506,113 - Reviews: 813 - Favs: 943 - Follows: 1,095 - Updated: 10/28 - Published: 10/11/2022 - Luke S., Han S., Master Chief/John-117, T. Lasky
Post Traumatic War Machines by The Shadowscythe reviews
The Spirit of Fire drifted for years after the destruction of the unknown forerunner shield world with it's digital angel clinging to life. The Battlestar Galactica has sent it's Raptor Compliment in search of precious water after it's holds had been sabotaged by a Cylon agent. Unseen hands have created an impossible meeting and now stars will tremble before humanities creations.
Crossover - Halo & Battlestar Galactica: 2003 - Rated: M - English - Sci-Fi/Drama - Chapters: 2 - Words: 6,534 - Reviews: 34 - Favs: 93 - Follows: 154 - Updated: 10/27 - Published: 10/25 - J. Cutter, E. Anders, Serina, W. Adama
Of Latchkeys and Misjumps by Sieben Nightwing reviews
When a second wave SLDF task force from the Amaris Civil War carrying high value passengers suffers a misjump, they end up in orbit over an uncharted planet. Lost and alone, they're hailed by an unknown ship. Circumstances will force them to work together to survive, as the new situation they find themselves in is even worse than the one they came from.
Crossover - Mechwarrior/Battletech & Halo - Rated: M - English - Sci-Fi/Adventure - Chapters: 10 - Words: 52,854 - Reviews: 22 - Favs: 66 - Follows: 102 - Updated: 10/26 - Published: 4/26
HaloHobbit by werecat1 reviews
A ship is dragged through a wormhole and crash lands on middle earth by the lonely mountain, can the crew help Bilbo and the Dwarrow take back the mountain?
Crossover - Halo & Hobbit - Rated: T - English - Sci-Fi/Fantasy - Chapters: 14 - Words: 26,639 - Reviews: 14 - Favs: 34 - Follows: 56 - Updated: 10/26 - Published: 9/4/2019
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