Mass Effect Crossovers
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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: 15 - Words: 91,382 - Reviews: 176 - Favs: 319 - Follows: 468 - Updated: 4/1 - Published: 8/7/2023
Robo Effect by Star Sage reviews
The Robotech wars are over. The survivors of Humanity and the Zentraedi are now alone in the universe, and so, come together, becoming something new, becoming Terrans. Now this race will find itself thrust into the galactic scene, as the Citadel Races and those beyond test these young upstarts, and in the shadows, old things begin to move.
Crossover - Robotech/Macross & Mass Effect - Rated: T - English - Sci-Fi/Adventure - Chapters: 66 - Words: 232,390 - Reviews: 644 - Favs: 935 - Follows: 1,022 - Updated: 4/1 - Published: 4/14/2015
Imperium Effect: Terra Rising by Deathwatch Razgriz reviews
The long awaited sequel to UNSC Pheonix Rising. The fledgling Empire has survived it's birthpains, and now looks to the stars to rebuild what was once theirs...
Crossover - Warhammer & Mass Effect - Rated: M - English - Humor/Sci-Fi - Chapters: 18 - Words: 88,240 - Reviews: 337 - Favs: 511 - Follows: 633 - Updated: 4/1 - Published: 8/4/2017
Helldivers: Vorcha Liberty by Jeggetts4.0 reviews
Ten years after the first galactic war, a new race that is in dire need of Managed Democracy is discovered. Soon, humanity will need them in return. For Super Earth.
Crossover - Mass Effect & Helldivers - Rated: T - English - Sci-Fi/Adventure - Chapters: 1 - Words: 1,403 - Reviews: 10 - Favs: 27 - Follows: 41 - Published: 3/31
The Traveler's Second Chance by Caldesan reviews
The Traveler has a different response to the Darkness. A story where the Guardians never accept the Darkness. The Traveler gave them a second chance, what do they do with it? Destiny shows up in Mass Effect. OC's for Destiny MC and Ghosts, different take on Destiny Lore
Crossover - Mass Effect & Destiny - Rated: M - English - Adventure/Romance - Chapters: 8 - Words: 75,912 - Reviews: 18 - Favs: 104 - Follows: 149 - Updated: 3/31 - Published: 8/6/2023
Mass Effect: Knights of the Force - Book 1: Rise of the Force by WK-94 reviews
As Reaper's cycle of extinction continues for eons, the Galaxy was in greater danger than anyone ever realized! The Force itself was threatened by countless cycles of extinction, and it reacted by bringing the Chosen One from different universe, who has great knowledge of Star Wars & Mass Effect. Will the he be able to save the Galaxy from the Reapers before it is all too late?
Crossover - Star Wars & Mass Effect - Rated: K+ - English - Sci-Fi/Parody - Chapters: 3 - Words: 12,022 - Reviews: 14 - Favs: 46 - Follows: 62 - Updated: 3/28 - Published: 3/24 - Darth Revan, Shepard, OC
World On Fire by WiseTomato reviews
The day the Reapers invaded Earth, one landed on Hogwarts. The castle survived, but the Statute of Secrecy won't.
Crossover - Harry Potter & Mass Effect - Rated: M - English - Fantasy/Adventure - Chapters: 3 - Words: 29,459 - Reviews: 201 - Favs: 1,089 - Follows: 1,486 - Updated: 3/28 - Published: 2/6/2018 - Harry P.
Mass Wars Episode II by Fantasymaker76 reviews
Five Years have past since the destruction of the Normandy and the death of Commander Shepard. Now a new order is rising in the unmapped regions of the galaxy which is leaving unease in both the Republic and the Citadel. Determined to find out what is going on, a pro-human organisation has made plans to find out what this mysterious group wants.
Crossover - Mass Effect & Star Wars - Rated: M - English - Sci-Fi/Adventure - Chapters: 8 - Words: 39,012 - Reviews: 16 - Favs: 36 - Follows: 39 - Updated: 3/28 - Published: 3/13/2023
Rising from the Embers of Sera by thehappy reviews
The people of Sera rebuild, spreading to the stars. Wars will be waged. Peace will be sought. The Coalition has risen from the ashes to take their right to exist in the galaxy. They will survive...no matter the cost.
Crossover - Gears of War & Mass Effect - Rated: M - English - Sci-Fi/Adventure - Chapters: 27 - Words: 408,031 - Reviews: 505 - Favs: 734 - Follows: 868 - Updated: 3/26 - Published: 12/28/2020 - OC, U. Wrex, Shepard, Councilor Tevos
The Big Stick by Digital-Chaos-85 reviews
The old girl's been around for almost 240 years. She served humanity for 39 of those and spent 160 as a museum, but now her fate lies in the scrap yards. Now, more than ever, the USS Iowa needs a new home under the stars. Come hell or highwater she'll get one.
Crossover - Mass Effect & Kantai Collection - Rated: T - English - Humor/Sci-Fi - Chapters: 1 - Words: 4,782 - Reviews: 6 - Favs: 20 - Follows: 35 - Published: 3/25 - OC, Iowa
Mass Effect: Forward Unto Dawn by WildcatWarrior67 reviews
Spartans never die. They're just missing in action. At least, that's how the saying goes. But for the Master Chief and Cortana, they're no longer missing. Awaking in a different universe, the two of them will uphold their oath: to protect Earth and all her colonies. Only it won't be from the Covenant this time.
Crossover - Halo & Mass Effect - Rated: T - English - Sci-Fi/Adventure - Chapters: 5 - Words: 10,714 - Reviews: 46 - Favs: 222 - Follows: 393 - Updated: 3/20 - Published: 11/26/2022 - Master Chief/John-117, Cortana, Shepard
Mass Effect: Resurrection by RabidRabbids reviews
Shepard's life hadn't gotten any easier. Entire colonies were disappearing, millions of people gone. And that's not even mentioning she'd been dead for two years, but desperate times call for desperate measures, and Shepard is forced to work with Cerberus to find out what's behind the disappearances. Thankfully, she's got monsters backing her up. (Sequel to Monstrum Immortalem)
Crossover - Mass Effect & Guardians of the Galaxy - Rated: M - English - Sci-Fi/Adventure - Chapters: 29 - Words: 135,072 - Reviews: 8 - Favs: 21 - Follows: 26 - Updated: 3/20 - Published: 6/15/2021
Judgement Effect by The Dullahan of Lore reviews
Having been cast into the ME-verse; Xander was 'saved' by a rogue scientist who took advantage of subconscious memories for the creation of A.I. Xander was transformed. he became...Skynet. YAHF!Xander. Rated M just in case at this point.
Crossover - Buffy: The Vampire Slayer & Mass Effect - Rated: M - English - Sci-Fi/Drama - Chapters: 6 - Words: 18,995 - Reviews: 33 - Favs: 130 - Follows: 181 - Updated: 3/20 - Published: 12/20/2023 - Xander H., Benezia
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: 11 - Words: 194,726 - Reviews: 55 - Favs: 106 - Follows: 120 - Updated: 3/20 - Published: 11/6/2021 - Imperial Guard, Tyranids, OC, Shepard
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: 6 - Words: 7,280 - Reviews: 1 - Favs: 2 - Follows: 5 - Updated: 3/19 - Published: 12/27/2023 - Mario, Luigi, Daisy, Toad
Were it So Easy by Sigma0327 reviews
Six's life was a giant war. Every battle was a test of sheer tenacity and stubbornness against insurmountable odds. Every moment, every bullet fired, every Covenant, Insurrectionist, and Flood spore killed has led up to his last fight. Once again he was one of the few that stood between Earth and her enemies. This would be his final battle, and nothing could change that, right?
Crossover - Halo & Mass Effect - Rated: M - English - Adventure/Sci-Fi - Chapters: 12 - Words: 165,032 - Reviews: 233 - Favs: 1,038 - Follows: 1,474 - Updated: 3/17 - Published: 11/9/2020 - SPARTAN-B312/Noble Six, Tali'Zorah, Miranda L., Shepard
Saiyan Effect by bored peasant reviews
The Citadel Council weren't ready for a species with the power of the saiyans at their back.
Crossover - Mass Effect & Dragon Ball Super - Rated: T - English - Sci-Fi/Adventure - Chapters: 19 - Words: 110,858 - Reviews: 855 - Favs: 2,146 - Follows: 2,570 - Updated: 3/15 - Published: 8/9/2017 - Son Gohan, Son Goku, Vegeta
Anthem Effect by DragonKnight374 reviews
What if more than the world of Coda was isolated in space time? What will the freelancers do when they realize there’s more to the universe than their little planet, and how will the citadel react, to the Anthem of Creation?
Crossover - Mass Effect & Anthem - Rated: M - English - Sci-Fi/Adventure - Chapters: 15 - Words: 76,702 - Reviews: 74 - Favs: 320 - Follows: 383 - Updated: 3/14 - Published: 8/8/2022
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: 45 - Words: 153,211 - Reviews: 63 - Favs: 289 - Follows: 306 - Updated: 3/12 - Published: 8/2/2019
Temporal Displacement with Gamer Characteristics by Keywielder reviews
As if shifting between the real world and Elite-verse when I had just graduated from Senior High for a few months wasn't enough, now they're telling me that it was a goddamned Beta THE WHOLE TIME, after FIVE FUCKING YEARS of God knows what in the actual fuck and ONLY NOW I get the full release! Fuck it. Let's just roll with this crap... Gamer, OC, SI. Current World: Mass Effect.
Crossover - Mass Effect & Elite Dangerous - Rated: M - English - Sci-Fi - Chapters: 7 - Words: 73,051 - Reviews: 67 - Favs: 345 - Follows: 436 - Updated: 3/10 - Published: 11/20/2021
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.
Crossover - Sonic the Hedgehog & Mass Effect - Rated: T - English - Sci-Fi/Fantasy - Chapters: 6 - Words: 62,746 - Reviews: 24 - Favs: 60 - Follows: 83 - Updated: 3/6 - Published: 11/26/2023 - Sonic, Tails, OC
Enthrallment Colors by undead3 reviews
Prince of the rogue human state, the Britannian Empire, Lelouch stumbles into grander conspiracies as he makes a bid for position within the Empire. Meanwhile Hana Shepard has been flung head first into a race against a renegade Spectre with the fate of all life in the balance. Are these two rising stars saviors, or destined to burn the galaxy in the flames of war?
Crossover - Code Geass & Mass Effect - Rated: M - English - Drama/Sci-Fi - Chapters: 16 - Words: 86,640 - Reviews: 49 - Favs: 57 - Follows: 68 - Updated: 3/5 - Published: 1/8 - Lelouch L., Kallen S., Shepard, Garrus V.
Place of Our Legacy by firstprime1230 reviews
Earth has been overrun by the forces of the Ori. Beaten, demoralized and on the run in the Ancient city of Atlantis the survivors of Earth make a desperate gamble to save what little they have left. Arriving in a galaxy so different from their own, can they uphold the legacy left to them by the races that came before? And save a galaxy doomed to a suffer a fate worse than death.
Crossover - Stargate: SG-1 & Mass Effect - Rated: T - English - Sci-Fi/Adventure - Chapters: 17 - Words: 254,012 - Reviews: 566 - Favs: 1,144 - Follows: 1,561 - Updated: 3/5 - Published: 4/30/2020
Opposing Effect by ego023
Adrian Shephard went through hell on black mesa. Now he finds himself in a different future and galaxy. Now he is ready to complete his task.
Crossover - Half-Life & Mass Effect - Rated: M - English - Sci-Fi/Adventure - Chapters: 1 - Words: 613 - Favs: 6 - Follows: 10 - Published: 3/4 - A. Shephard, OC, Shepard
RWBY Effect 2: Rebirth by Owriush reviews
A year and a half has gone by, since the attack on the Citadel. Team RWBY and the crew of the Normandy suffer a tragedy. Ending in the loss of many lives. Awakened now a few years later. The girls of team RWBY, Elizabeth Shepard and their new allies must fight against a threat. One even more dangerous then the last. This is their Rebirth into a new world of wonders and insanity.
Crossover - Mass Effect & RWBY - Rated: T - English - Adventure/Romance - Chapters: 4 - Words: 66,224 - Reviews: 7 - Favs: 36 - Follows: 39 - Updated: 3/4 - Published: 8/10/2022
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