Mass Effect Crossovers
Filters
3.6K | Page 1 2 3 4 11 .. Last Next »

The Prelude to War by Indigard reviews
A very different Mass Effect galaxy encounters a strange and relentless invader that is in constant hunger for Biomass but they never know it's just a glimpse of what is coming for them. Featuring: an alternative history for every species, a bigger and more populated galaxy, cunning Asari, and a militarized and Germanized human empire.
Crossover - Warhammer & Mass Effect - Rated: T - English - Chapters: 13 - Words: 217,358 - Reviews: 62 - Favs: 120 - Follows: 138 - Updated: 46m - Published: 11/6/2021 - Imperial Guard, Tyranids, OC, Shepard
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: 53 - Words: 1,145,155 - Reviews: 952 - Favs: 661 - Follows: 736 - Updated: 5h - Published: 4/22/2016 - Master Chief/John-117, Cortana, Tali'Zorah, Shepard
Let There Be Light (Rewrite) by Phorus Aedelmaer reviews
As old stars flicker and ancient powers stir, a spark ignites between two great civilizations—one forged in faith and fire, the other in diplomacy and design. In the void between worlds, first contact becomes a crucible. What emerges will reshape the fate of the galaxy.
Crossover - Warhammer & Mass Effect - Rated: T - English - Sci-Fi/Fantasy - Chapters: 3 - Words: 10,725 - Reviews: 24 - Favs: 63 - Follows: 90 - Updated: 20h - Published: 3/22 - The Emperor, Primarch/s
Effects of Man by Krotosin reviews
During the shitshow that Eden Prime was, Shepard finds a man buried near the Beacon. With him, two AIs, one from Reach, the other from Typhon. With him at her side, Jane's mission is easier. If it wasn't for the fact he's a hyper-lethal killing machine, with malware stuck in his head. And a bit of an odd case. Mostly Titanfall and Halo, with some (a lot) Deep Rock Galactic.
Crossover - Mass Effect & Titanfall - Rated: M - English - Sci-Fi/Adventure - Chapters: 8 - Words: 48,907 - Reviews: 15 - Favs: 139 - Follows: 176 - Updated: 3/26 - Published: 6/10/2023 - OC
What Lies Beneath by Mandalorian Runescaper reviews
After Commander Shepard refuses her help on the Citadel, Tali is left having to find another way to complete her Pilgrimage. But there are other things in the galaxy just as terrifying as the Reapers. Mass Effect/Alien crossover, but with much more of a focus on the former. Takes place during ME1. Feedback is much appreciated!
Crossover - Aliens/Predator & Mass Effect - Rated: T - English - Sci-Fi/Horror - Chapters: 5 - Words: 30,283 - Reviews: 18 - Favs: 31 - Follows: 35 - Updated: 3/25 - Published: 12/17/2022 - Tali'Zorah, OC
Marathon Effect by IX404 reviews
After dying thousands of times, and winning hopeless encounters, Roland Hector, Chief Security Officer of the UESC Marathon, also known as Mjolnir Recon number 54, finally succeeds in trapping the W'rkncacntr. Little does Roland and Durandal know is that they will soon be involved in another race against an enemy that seeks to destroy Humanity and it's allies.
Crossover - Marathon & Mass Effect - Rated: T - English - Sci-Fi/Adventure - Chapters: 5 - Words: 24,758 - Reviews: 23 - Favs: 42 - Follows: 65 - Updated: 3/24 - Published: 11/20/2024 - Durandal, Cyborg, Garrus V., Shepard
The Call to War by silencewillfall0091 reviews
In 2550 CE, 25 years into our war with the Covenant, a Turian fleet exploded out of the ice moon orbiting Lusitania. The Hierarchy, aching for a war since the humiliation of the Rachni invasion, stumbled into the most brutal conflict in recent galactic history.
Crossover - Halo & Mass Effect - Rated: T - English - Sci-Fi/Adventure - Chapters: 2 - Words: 4,022 - Reviews: 18 - Favs: 98 - Follows: 145 - Updated: 3/24 - Published: 2/2
Book One: Harvest by Believer218 reviews
The year is 2583. Humanity stands strong, even twenty-six years after a disastrous first contact. But it seems that wherever they go, war will follow. And this war will grip the galaxy like no other. The first adventure of Mass Effect: The Reclaimer Saga. Rated M for graphic depictions of violence.
Crossover - Halo & Mass Effect - Rated: M - English - Sci-Fi/Adventure - Chapters: 9 - Words: 42,184 - Reviews: 120 - Favs: 130 - Follows: 187 - Updated: 3/23 - Published: 4/4/2024 - [Master Chief/John-117, Ashley W.] Arbiter, Saren A.
The Tale of Thomas Prometheus by avrjoe reviews
A secret organization of AU traveling immoral researchers kidnap a man from our world and subject him to cruel augmentation experiments. When an unknown force attacks, our protagonist finds himself the only one left alive. Taking the name Thomas Prometheus, he plots to both train himself and gather a team to end the organization behind his kidnapping.
Crossover - X-overs & Mass Effect - Rated: T - English - Adventure - Chapters: 4 - Words: 10,150 - Reviews: 1 - Favs: 4 - Follows: 8 - Updated: 3/23 - Published: 3/4 - Shepard
The Chitinous Nightmare by RedFrontWriter reviews
Setting out into the galaxy for her pilgrimage, Tali'Zorah nar Rayya finds work with a human colony on the moon, LV-426. It is not long however, before she and the other colonists find themselves trapped in a nightmare from which there is increasingly little chance of escape.
Crossover - Aliens/Predator & Mass Effect - Rated: T - English - Horror/Sci-Fi - Chapters: 4 - Words: 16,134 - Reviews: 15 - Favs: 12 - Follows: 15 - Updated: 3/22 - Published: 3/2 - Newt, Amanda R., Tali'Zorah, Saren A.
Echoes of the Forerunners: A Covenant Unveiled (Hiatus) by Phorus Aedelmaer reviews
The Covenant War erupts with far-reaching consequences across two universes. As the UNSC struggles to survive, they form an unexpected alliance with the species of the Citadel Council. Creative liberties will be taken with the timelines, events, and characters of both franchises.
Crossover - Halo & Mass Effect - Rated: K+ - English - Sci-Fi - Chapters: 18 - Words: 33,532 - Reviews: 165 - Favs: 193 - Follows: 275 - Updated: 3/22 - Published: 9/8/2024 - Complete
Let There Be Light (To Be Rewritten) by Phorus Aedelmaer reviews
The Imperium of Man arrives in the Mass Effect galaxy, igniting war with the Citadel Council. As the Imperium sees only heresy, the Council scrambles to survive. The Reapers, faced with an empire that defies their cycle, prepare to adapt. With war looming, the fate of the galaxy hinges on whether diplomacy or extermination prevails.
Crossover - Warhammer & Mass Effect - Rated: T - English - Sci-Fi/Fantasy - Chapters: 12 - Words: 23,442 - Reviews: 77 - Favs: 181 - Follows: 216 - Updated: 3/22 - Published: 1/29 - Complete
The Reclaimer Wars:The Reaper Crisis by Johnnieboy11 reviews
Six months prior to the worst crisis the normal Milky Way would face, Commander Shepard hunts the Collectors abducting human colonists in the Terminus Systems when she comes upon a terrifying new sight:Three Intergalactic fleets arrayed against each-other and her sole Frigate. Three new factions, one seeking a home and two seeking answers, all linked by the Star Roads.
Crossover - Game X-overs & Mass Effect - Rated: T - English - Sci-Fi/Adventure - Chapters: 45 - Words: 259,875 - Reviews: 283 - Favs: 318 - Follows: 382 - Updated: 3/21 - Published: 4/26/2024 - Liara T'Soni, Tali'Zorah, Miranda L., Shepard
Tali'Zorah: Demonologist by Sheev314 reviews
I DO NOT OWN MASS EFFECT ALSO THE FIRST TWO CHAPTERS WILL HAVE HORROR ELEMENTS IN IT Tali'Zorah's pilgrimage on a haunted world turns into an adventure with the demon known as Shepard. Can she and her new infernal friend save the galaxy from the Reapers, or will the universe burn in the fires of a new war.
Crossover - Mass Effect & Pathfinder RPG - Rated: M - English - Sci-Fi/Horror - Chapters: 5 - Words: 26,454 - Reviews: 15 - Favs: 32 - Follows: 42 - Updated: 3/21 - Published: 11/19/2024 - Tali'Zorah, Shepard
The True Way Of The Sith - Part Two by Writing Shop 12 reviews
Sequel to The True Way Of The Sith. The Mass Effect Relay has been activated and a whole new galaxy of opportunity comes with it. What will Lily Potter, the Crown Princess of the Sith Empire, do with this new chance for adventure? And more importantly, will her father let her go into the unknown on her own? Citadel space beware, the Sith have come. (Harry x Harem) (Lily x Shepard)
Crossover - Harry Potter & Mass Effect - Rated: M - English - Adventure/Romance - Chapters: 8 - Words: 41,138 - Reviews: 509 - Favs: 2,771 - Follows: 3,517 - Updated: 3/21 - Published: 1/8/2023 - Harry P., Liara T'Soni, Tali'Zorah, Shepard
Mass Effect: Become Legend by Redgrave21 reviews
More than five years after the Reaper War, Jane Shepard had lost her life for her galaxy, while Garrus Vakarian struggles to move on from the loss of the love of his. But when Garrus begins to suffer strange dreams, the Normandy crew are thrust into a conflict that has lasted since the beginning of time. All the while a strange voice begins to tempt Garrus with… Salvation.
Crossover - Destiny & Mass Effect - Rated: M - English - Adventure/Romance - Chapters: 32 - Words: 199,684 - Reviews: 106 - Favs: 62 - Follows: 83 - Updated: 3/21 - Published: 7/7/2024 - Garrus V., Shepard, Osiris, Cayde-6
Mass Effect demi humans by EclipsePheniox reviews
Long ago on earth demi-humans appeared on earth. Now expanding into the galaxy the other races have to deal with both humans and demi-humans. Mass effect story from beginning to end but with monster people to make it more interesting. Experimental, possible harem
Crossover - Mass Effect & Monster Girl Encyclopedia - Rated: M - English - Adventure/Sci-Fi - Chapters: 51 - Words: 168,710 - Reviews: 71 - Favs: 324 - Follows: 343 - Updated: 3/21 - Published: 8/2/2019
Mario Effect by OroDeus reviews
Haunted by visions of impending doom, Mario summons his ragtag team of explorers to adventure. Their journey across the stars will uncover the koopa king's horrible plot to take over the galaxy.
Crossover - Mario & Mass Effect - Rated: M - English - Sci-Fi/Adventure - Chapters: 33 - Words: 38,777 - Reviews: 15 - Favs: 4 - Follows: 7 - Updated: 3/20 - Published: 12/27/2023 - Mario, Luigi, Daisy, Toad
Operation ECLIPSE by HelenTheMoon reviews
Pre-ME1 post-Frontiers Xover, in which the Sonic version of Earth replaces ME Earth. A Batarian planet suddenly turns invisible, and things only get weirder from there. That poor STG agent won't know what hit him, that's for sure. And neither will the rest of the galaxy - once Sonic and Eggman get there. Crossposted on Spacebattles and AO3. Rating may change. NOW ON TV TROPES!
Crossover - Sonic the Hedgehog & Mass Effect - Rated: T - English - Sci-Fi/Fantasy - Chapters: 14 - Words: 157,611 - Reviews: 88 - Favs: 125 - Follows: 151 - Updated: 3/20 - Published: 11/26/2023 - Sonic, Tails, OC
Merged Stars by Lord of the Wall reviews
Through unknown forces of immense and unimaginable power, two galaxies merge and superpowers of both galaxies is forced to deal with the reality of the broken status quo. Jane Shepard, first human Spectre, finds herself in the center of the events to come. This is a 3-way crossover between the forementioned ME and Halo universes as well as Stargate. Knowledge of all are not needed.
Crossover - Halo & Mass Effect - Rated: T - English - Sci-Fi/Family - Chapters: 2 - Words: 10,406 - Reviews: 11 - Favs: 58 - Follows: 78 - Published: 3/20 - Master Chief/John-117, T. Hood, Atriox, Shepard
Mobile Suit - Mass Effect: The First Contact War by Mister Smallville reviews
Two worlds collide, neither prepared for the other. The Solar Sphere Congress -successor to the long gone Earth Federation- unwittingly starts a galactic crisis when it makes first contact with a very angry, very trigger happy Turian Hierarchy.
Crossover - Gundam UC & Mass Effect - Rated: T - English - Sci-Fi - Chapters: 30 - Words: 197,721 - Reviews: 360 - Favs: 514 - Follows: 695 - Updated: 3/20 - Published: 8/7/2023
Nine Tails Tales :Kyubi Effect by Ninja65 reviews
Naruto has lived an interesting life. This is the story of his life after his original one. Full of adventures and technology Naruto couldn't have even fathomed. Will he find himself in this new life he has to start. Will he find love even ... Heck yea he will. Naruto x Harem SlightAU Naruto
Crossover - Naruto & Mass Effect - Rated: M - English - Adventure/Romance - Chapters: 8 - Words: 36,188 - Reviews: 45 - Favs: 249 - Follows: 323 - Updated: 3/19 - Published: 10/3/2021 - Naruto U., Hinata H., Liara T'Soni, Tali'Zorah
Mass Effect: Legend of Vader by Gaming Lichdom reviews
Darth Vader attempts to resurrect his deceased wife through an ancient ritual, but is pulled into the machine and transported to an unknown planet. On his quest to return home, he comes across a Quarian woman named Tali'Zorah, who just so happens to have information about a rogue Spectre Named Saren. The two form a strange duo as they venture on a quest to save the galaxy.
Crossover - Star Wars & Mass Effect - Rated: T - English - Sci-Fi/Adventure - Chapters: 4 - Words: 18,031 - Reviews: 42 - Favs: 160 - Follows: 249 - Updated: 3/19 - Published: 10/30/2024 - [Darth Vader, Tali'Zorah] Garrus V., Shepard
Estrella y Masa se Conocen by dark platinum reviews
Anthon fankhauser y John Shepard son dos individuos reconocidos por sus respectivos gobiernos como héroes de renombre, la única diferencia es la escala en la que operan, uno a salvado a un sector entero mientras que el otro a salvado a una galaxia entera, que ocurrirá cuando el primero se encuentre con el segundo.
Crossover - Mass Effect & Starfield - Rated: M - Spanish - Adventure/Sci-Fi - Chapters: 4 - Words: 42,849 - Reviews: 4 - Favs: 8 - Follows: 9 - Updated: 3/18 - Published: 5/24/2024 - Miranda L., Shepard, Sarah Morgan, OC
Mass Effect: ODST Lost by Fantasy Theatre 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.
Crossover - Halo & Mass Effect - Rated: M - English - Sci-Fi/Adventure - Chapters: 6 - Words: 19,811 - Reviews: 26 - Favs: 128 - Follows: 193 - Updated: 3/18 - Published: 4/24/2022 - OC, Ashley W., Tali'Zorah, Shepard
3.6K | Page 1 2 3 4 11 .. Last Next »