Halo and Mass Effect Crossovers
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Daily war with monster girls by Masterdude21 reviews
With the help of the highly-motivated extra-species in the military, mankind holds their own against the brutal onslaught of the Covenant. In their haste to close the gap in space warfare, ONI stumbles upon Relay 314. Even as new enemies arise, the galaxy constantly thwarts Cortana's schemes to build the Master Chief the ultimate harem. Halo/Mass Effect/Monster Musume crossover.
Rated: M - English - Humor/Romance - Chapters: 28 - Words: 383,980 - Reviews: 1089 - Favs: 2,169 - Follows: 2,426 - Updated: 10/28/2022 - Published: 9/20/2016 - Master Chief/John-117, Cortana, Shepard
The Might of Humanity by The Grandiose Library reviews
In Progress
Rated: M - English - Adventure/Sci-Fi - Chapters: 1 - Words: 6,741 - Reviews: 15 - Favs: 100 - Follows: 116 - Published: 8/16/2022
Mass Effect Terran Effect by The Grandiose Library reviews
Work In Progress
Rated: T - English - Sci-Fi - Chapters: 1 - Words: 695 - Reviews: 3 - Favs: 31 - Follows: 40 - Published: 8/16/2022
Predating Prelates by Lighting wolf knight reviews
The one ship that ends up here and it changes so much... Rated T for violence, death, and profanity.
Rated: T - English - Adventure/Sci-Fi - Chapters: 1 - Words: 827 - Reviews: 3 - Favs: 7 - Follows: 12 - Published: 8/2/2022 - OC, Shepard, Peebee S.
The Halo Effect: War and Civilization by free man writer reviews
A crossover years in the works. Civilizations rise and fall but to those that do stand, they prosper. They Expand. They reach out across the stars. But of course, such is a Universal law, War is never far behind. War is a language all civilized races speak and it is war most are familiar with. Co-written with BulletStormX. Halo/Mass Effect with a dash of Star Wars.
Rated: M - English - Sci-Fi/Adventure - Chapters: 13 - Words: 127,353 - Reviews: 372 - Favs: 823 - Follows: 1,060 - Updated: 7/4/2022 - Published: 7/28/2020
Xen Effect by ThePilotArchangel reviews
Xen is the gateway between universes and dimensions. It is the place where time, space, physics, and other known rules that define ones life go out the metaphorical window. What will happen when a Child of Xen, a perfect Supersoldier, a Guardian of Humanity, and a Spectre of a Council of aliens find themselves caught up in a war of survival? Find out in "Xen Effect".
Rated: T - English - Sci-Fi/Adventure - Chapters: 8 - Words: 73,718 - Reviews: 41 - Favs: 103 - Follows: 126 - Updated: 7/4/2022 - Published: 4/30/2022 - Master Chief/John-117, Cortana, Shepard, OC
HALO Mass convergence by SapphireDawn11709 reviews
Two Universe collide after the Forerunners fall and the Reapers return, will the two branches of Humanity placed in their respective Systems by a Forerunner Monitor unite or fall, only time will tell in this epic clash. When the UNSC Exploration and Research Vessel Light of Sol discover a strange artifact, they are opened up to the rest of the Galaxy after millennia of isolation.
Rated: M - English - Sci-Fi - Chapters: 24 - Words: 82,670 - Reviews: 329 - Favs: 763 - Follows: 957 - Updated: 7/4/2022 - Published: 9/18/2016 - Master Chief/John-117, Cortana, J. Garson, Tali'Zorah
Mass Effect - Convergence by Fallen2Pancake reviews
During a Batarian Slave Raid on the Systems Alliance Colony of Eden Prime unknown defenders both Human and of unknown alien origin aid in the defense. While the UNSC and XCOM join forces under a thought long dead UNSC Rear Admiral and navigate this new universe, how will the future of Mass Effect change and will it change for the better or worse. - Mass Effect - Halo - XCOM Cross.
Rated: M - English - Sci-Fi - Chapters: 1 - Words: 11,385 - Reviews: 12 - Favs: 97 - Follows: 136 - Published: 7/2/2022 - SPARTAN-B312/Noble Six, OC, Admiral Hackett, Shepard
Heroes UNITE! by So-Pro Warrior reviews
Commander Shepard and his team have gathered together the races of their Galaxy in an effort to defeat the Reapers. But is it enough? When the team comes across a strange woman they find out that if they are to truly defeat the Reapers once and for all. They will need all the help they can get. But not from their Universe. Multiverse Crossover! Chapters 6-22 Being Rewritten!
Rated: T - English - Adventure/Sci-Fi - Chapters: 49 - Words: 1,514,387 - Reviews: 906 - Favs: 452 - Follows: 426 - Updated: 6/14/2022 - Published: 6/21/2013 - Master Chief/John-117, Shepard - Complete
The Great Galactic War by hellothere45 reviews
Occurs after the events of Halo Infinite. Cortina finds out about a new enemy from the void of space called the reapers who are trying to rule the galaxy sending a warning to her former allies and enemies to unite the, she assigns chief espranza and the Weapon on a mission to unite the Citadel species to fight a war to end all wars in the Galaxy, can they do this task
Rated: T - English - Sci-Fi/Adventure - Chapters: 3 - Words: 4,068 - Reviews: 17 - Favs: 30 - Follows: 41 - Updated: 6/9/2022 - Published: 6/3/2022
Rise of Humanity by James118 reviews
Soon after the war with the Covenant, humanity discovers a Mass Relay that opens the door to the rest of the galaxy. But it also awakens the greatest threat humanity has ever faced. Male Shepard/Liara. OC/Krystal (from Star Fox).
Rated: M - English - Adventure/Sci-Fi - Chapters: 2 - Words: 22,101 - Reviews: 21 - Favs: 114 - Follows: 156 - Updated: 5/31/2022 - Published: 5/21/2022 - [Shepard, Liara T'Soni] OC
Spirit of Fire by GoldenThorns-Fiverr reviews
A Crossover fanfic I did as a Fiverr request.
Rated: T - English - Chapters: 1 - Words: 7,853 - Reviews: 3 - Favs: 10 - Follows: 12 - Published: 5/24/2022 - Complete
Mass Effect - Orion (Discontinued) by Fallen2Pancake reviews
This is a Mass Effect - Halo - XCOM Crossover. In the year 2084 during the Asteroid Belt Offensive XCOM Elite Unit Strike-1 discovers an Ethereal Station but must Psionic Teleport away but something goes wrong. In the Year 2552 the UNSC Fearless an Orion-Class Assault Carrier is forced to escape Reach under heavy fire, during the Slipsapce Transit something goes wrong.
Rated: M - English - Sci-Fi - Chapters: 8 - Words: 61,867 - Reviews: 69 - Favs: 173 - Follows: 249 - Updated: 5/13/2022 - Published: 4/16/2022 - SPARTAN-B312/Noble Six, Rookie, D. Anderson, Shepard
War and peace by Curiously intrigued reviews
The reapers brings new galactic superpowers into the war after invading the Orion arm of the galaxy. will the conflict unite them against a common foe or will they open conflict with each other.
Rated: M - English - Sci-Fi/Adventure - Chapters: 2 - Words: 2,510 - Reviews: 12 - Favs: 52 - Follows: 92 - Updated: 5/11/2022 - Published: 5/5/2022
Mass Effect: ODST Lost by Stardew's Stardrop reviews
ODST Captain Nathanial Renkov unintentionally becomes the first Helljumper to survive being dropped through a Slipspace anomaly. The problem? He has no idea where is and is surrounded by aliens the UNSC has no record of. Even worse? No one knows what the UNSC is. Follow his story as he tries to make sense of his new surroundings while trying to survive a new galactic threat.
Rated: M - English - Sci-Fi/Adventure - Chapters: 4 - Words: 15,072 - Reviews: 20 - Favs: 101 - Follows: 149 - Updated: 5/11/2022 - Published: 4/24/2022 - OC, Ashley W., Tali'Zorah, Shepard
The Way the World Ends by Canelo312 reviews
AU. Spartans never die. But we all know that's not true. A terrifying new enemy approaches and only time will tell if the forces that be can stop them.
Rated: M - English - Sci-Fi/Adventure - Chapters: 1 - Words: 25,002 - Reviews: 8 - Favs: 55 - Follows: 79 - Published: 5/7/2022 - Master Chief/John-117, SPARTAN-B312/Noble Six, Liara T'Soni, Shepard
Halo: A New Journey by mgarner3199 reviews
Master Chief wakes up in the Mass Effect universe and joins Commander Shepard in an effort to stop the Reapers. With time running out, can they stop the extinction of every species, or will they fade into legend?First, they got to stop the Reapers though...
Rated: K - English - Sci-Fi/Romance - Chapters: 3 - Words: 3,002 - Reviews: 15 - Favs: 38 - Follows: 74 - Updated: 4/27/2022 - Published: 12/7/2021 - Cortana, Master Chief/John-117, Illusive Man, Shepard
The Canadian Commonwealth by Vassago1991 reviews
In the vast multiverse events can happen that should never happen this is the story of one such event in a a universe that was should never have been.
Rated: M - English - Chapters: 3 - Words: 17,333 - Reviews: 15 - Favs: 54 - Follows: 55 - Updated: 4/26/2022 - Published: 2/24/2022
The voyage of Valiant by Lighting wolf knight reviews
There was more on the line... Yet plans and webs were made. Rated T for violence, death, and profanity.
Rated: T - English - Sci-Fi/Adventure - Chapters: 1 - Words: 811 - Reviews: 1 - Favs: 5 - Follows: 9 - Published: 4/20/2022 - Miranda K., D. Whitcomb, OC, Shepard
Noble Effect by LoneSpartan52 reviews
Noble Six was alone after the death of Emile. The Pillar of Autumn had left Reach, leaving the lone Spartan behind. But what if instead of dying on Reach, fighting to his last breath, Six survived? What if he escaped Reach and headed for Earth, only to end up in another galaxy, in another war? Will he agree to fight the reapers alongside aliens? Find out in Noble Effect
Rated: T - English - Sci-Fi - Chapters: 16 - Words: 62,375 - Reviews: 129 - Favs: 377 - Follows: 519 - Updated: 4/19/2022 - Published: 7/3/2020 - SPARTAN-B312/Noble Six, Garrus V., Shepard, Javik
Reckoning of the Reclaimers (v2) by metts101 reviews
After the Great War Humanity was a different creature. Their brush with extinction left them cold and vengeful, and so they sought revenge for the transgressions of the Covenant species. With their eradication Humanity, driven by xenophobia, took their position as the unrivalled power in the galaxy. However, will a xenophilic alien federation, in a new galaxy, change their outlook?
Rated: T - English - Sci-Fi - Chapters: 2 - Words: 14,933 - Reviews: 47 - Favs: 270 - Follows: 382 - Updated: 4/1/2022 - Published: 9/24/2021
Audax Novus by A-01 reviews
A bold new world - A strange new reality - Fresh trials, tribulations, allies, and enemies. John fell through the portal from the Mantles Approach, but his luck works in mysterious ways. Now stranded in an alternate reality, how will he strive forward? The galaxy takes a sharp turn from the world we know, and the Reaper threat looms just as large, but no longer so uncontested.
Rated: M - English - Adventure/Romance - Chapters: 25 - Words: 656,164 - Reviews: 774 - Favs: 1,706 - Follows: 2,105 - Updated: 2/17/2022 - Published: 9/4/2020 - [Master Chief/John-117, Miranda L.] [Shepard, Tali'Zorah]
To Be the Last by Bruanshan Never-Seen reviews
A Halo/Mass Effect crossover, though not a typical one. This is the story of the last Forerunner, sent to a different galaxy entirely. How will he handle himself in this new glaxy where everything is different. Adopted from drich147. I corrected a mistake in chapter 3 regarding how long he has been there. I do not own Mass Effect or Halo.
Rated: M - English - Adventure - Chapters: 3 - Words: 13,070 - Reviews: 235 - Favs: 442 - Follows: 512 - Updated: 1/13/2022 - Published: 7/28/2012 - Didact
Voyage unto Infinity by supertruckin reviews
The USS Voyager comes face to face with the massive ship that is the UNSC Infinity after Voyager's nearly fatal first test of their quantum slipstream drive. Getting home isn't their only issue. They will have to work together in order to unravel the ancient threat that plagues the new galaxy that they find themselves in. Star Trek:Voyager, Mass Effect, and Halo triple crossover
Rated: T - English - Sci-Fi/Adventure - Chapters: 15 - Words: 79,399 - Reviews: 643 - Favs: 1,724 - Follows: 2,233 - Updated: 1/2/2022 - Published: 4/10/2019 - Master Chief/John-117, Cortana, Shepard
An Old Machine's New Home by Edgeoftoday reviews
A Reaper is launched from it's home galaxy during one of their many cycles, and spends countless years floating through the empty void of space. It's unintended destination results in the nearly destroyed machine unknowingly put in the middle of a galactic war between a coalition of religeous zealots and an ambitious race expanding over the stars. Picks up at the start of Halo: CE.
Rated: T - English - Sci-Fi/Adventure - Chapters: 6 - Words: 29,509 - Reviews: 77 - Favs: 271 - Follows: 372 - Updated: 12/25/2021 - Published: 8/22/2020 - Master Chief/John-117, Arbiter, J. Keyes, Cortana
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