X-Com Crossovers
Filters
72 | Page 1 .. Last Next »

La mariposa, el Doctor y el etáreo by Zues Killer Productions reviews
During an uneventful day, Star and Marco follow a strange man to a place...unfortunately, something attacks them while they are in the dimensional tunnel, what follows is an extraordinary series of events to save a world...
Crossover - X-Com & Star Vs. The Forces of Evil - Rated: T - English - Friendship/Drama - Chapters: 4 - Words: 4,738 - Reviews: 2 - Updated: 8/24 - Published: 7/26
A Confederation, A Citadel, and a Commander by Tabac Iberez reviews
nuXCOM/ME When LTC Shepard is called back to duty after admin leave, he doesn't expect anything serious. Certainly not an assignment to Citadel space, his own independent command, or discovering that the diffrence between geting told something and learning about it are as different as cake and pie. Between inter-species screwups and politicos at home, things are gonna get hairy.
Crossover - X-Com & Mass Effect - Rated: T - English - Sci-Fi/Adventure - Chapters: 3 - Words: 5,237 - Reviews: 7 - Favs: 11 - Follows: 28 - Updated: 8/19 - Published: 8/14
Psi Effect by Cap'n Chryssalid reviews
A fun-loving asari mercenary finds herself a little in over her head when she ends up abducted by terrifying aliens from beyond the galactic frontier. These asari-like creatures call themselves 'humans.' They seem to be secretly nosing about on the borders of known space, acting through proxies, conducting covert operations, and they've got a deal for an enterprising asari...
Crossover - X-Com & Mass Effect - Rated: T - English - Humor/Sci-Fi - Chapters: 17 - Words: 164,180 - Reviews: 557 - Favs: 1,563 - Follows: 1,888 - Updated: 8/12 - Published: 7/19/2014 - U. Wrex, Daro'Xen, Shepard (F), OC
Finally, A Death Prevented by Urza3142 reviews
For a medieval universe, there aren't a lot of people around to save Elodie from certain death. Things were getting so out of hand that the powers that be decided to send another universe's heroes to mix things up. Rated T for language. One Shot. All XCOM soldiers are OC.
Crossover - X-Com & Long Live the Queen - Rated: T - English - Sci-Fi - Chapters: 1 - Words: 5,174 - Reviews: 1 - Favs: 1 - Follows: 2 - Published: 8/10 - Elodie - Complete
Nostrom Custodimus a Tenabris, We Watch From the Shadows by Seras is love reviews
After the Anglo-American Bio Terrorism Incident, World Leaders decided that the UN was not strong enough to maintain peace. The most powerful nations of the Security Council met in secret to discuss plans for a response unit capable of detecting a preventing future incidents. An unexpected threat from beyond Earth places this unit in league with the shadowy Hellsing organization.
Crossover - X-Com & Hellsing - Rated: T - English - Supernatural/Sci-Fi - Chapters: 8 - Words: 10,604 - Reviews: 10 - Favs: 15 - Follows: 25 - Updated: 8/6 - Published: 7/20
X-marks the Steven by du911 reviews
Post-Jailbreak AU! Upset with the recent invasion, X-com mobilizes on Beach City...Try not to blow up Steven guys! Inspired by Psykotic Addiction and Hotpoint!
Crossover - X-Com & Steven Universe - Rated: T - English - Supernatural/Sci-Fi - Chapters: 1 - Words: 253 - Reviews: 1 - Favs: 1 - Follows: 2 - Published: 8/5 - Steven U.
X-Com Into Darkness by deathwing17 reviews
After an information gathering mission in China, The leaders of X-Com learn that something strange is going on in Japan. They send a team in to investigate only for them to find something more disturbing than they originally feared.
Crossover - X-Com & Brynhildr in the Darkness/極黒のブリュンヒルデ - Rated: T - English - Sci-Fi/Horror - Chapters: 6 - Words: 34,884 - Reviews: 14 - Favs: 21 - Follows: 28 - Updated: 7/27 - Published: 8/12/2014
Vigil: Codex and Supplemental Information by Peptuck reviews
Supplemental information for the Vigil Mass Effect/XCOM/Eclipse Phase/FEAR/Destiny crossover setting. Arranged by topic. Will be updated as new information becomes available in the main storyline.
Crossover - X-Com & Mass Effect - Rated: K+ - English - Chapters: 3 - Words: 20,887 - Reviews: 1 - Favs: 24 - Follows: 16 - Published: 7/26
Vigil by Peptuck reviews
Mankind has survived its crucible, and while scarred and changed by the Ethereals, they advance into the cosmos. The galaxy beyond is a place of wonder and terror, of wealth and strife. Amid the threats and opportunities, both within and without, XCOM remains vigilant. Mass Effect/XCOM/Eclipse Phase/FEAR/Destiny fusion.
Crossover - X-Com & Mass Effect - Rated: T - English - Sci-Fi/Adventure - Chapters: 15 - Words: 141,167 - Reviews: 366 - Favs: 668 - Follows: 747 - Updated: 7/26 - Published: 9/2/2014
Smoke on the Water by P.H. Wise reviews
Centuries after the Ethereal war, after humanity discovered a galaxy filled with alien life, after the defeat of Sovereign, the abductions have begun again. This time, entire human colonies are disappearing. And a reborn Commander Shepard and the long-thought defunct Extraterrestrial Combat Unit may be the only thing standing between humanity and extinction... (XCOM/Mass Effect)
Crossover - X-Com & Mass Effect - Rated: T - English - Sci-Fi - Chapters: 8 - Words: 76,039 - Reviews: 44 - Favs: 141 - Follows: 213 - Updated: 7/17 - Published: 7/19/2014 - Shepard (F), Liara T'Soni, Miranda L.
Council's notes on Humanity by 5 Coloured Walker reviews
This is the Citadel Codex as it applies to Humans in the [TBD] world, who's current stories include: Busy Stars This however is not the codex of general things however, not is it human's documentation on aliens.
Crossover - X-Com & Mass Effect - Rated: T - English - Sci-Fi - Chapters: 8 - Words: 8,566 - Reviews: 1 - Favs: 27 - Follows: 24 - Updated: 7/6 - Published: 2/11
Of Psychics and Flying Chthulu-ships by Dr1ft3r0I reviews
The Volunteer ended the war. Now he and the best of X-Com are stuck in a world that they don't know, surrounded by aliens that may or may not want to kill them all. Oh, and there's a giant metal cuttlefish in the sky. Starts post X-COM: EU, beginning of ME1. Not CRACK!
Crossover - X-Com & Mass Effect - Rated: T - English - Adventure/Sci-Fi - Chapters: 4 - Words: 14,349 - Reviews: 33 - Favs: 77 - Follows: 149 - Updated: 7/3 - Published: 4/29 - [Shepard (F), Garrus V.]
Ferris by Jonn Wood reviews
A geek ends up in the XCOM universe. Good News: He's just the Chief Engineer's personal assistant. Bad News: The Chief Engineer is Tony Stark.
Crossover - X-Com & Ironman - Rated: T - English - Sci-Fi/Drama - Chapters: 24 - Words: 94,070 - Reviews: 31 - Favs: 65 - Follows: 84 - Updated: 6/30 - Published: 1/8/2014 - A. E. Stark/Tony
Re-activation by skyfire777 reviews
After the war, XCOM was reduced to conspiracy theories and urban myths. They did not exist in any shape or form. But they were far from gone. Now, after 50 years of rebuilding, humanity faces yet another threat. Now, after 50 years of preparations, XCOM stands ready to face that threat. Covert!XCOM. Rating subject to change
Crossover - X-Com & Mass Effect - Rated: T - English - Sci-Fi/Suspense - Chapters: 4 - Words: 5,775 - Reviews: 14 - Favs: 61 - Follows: 123 - Updated: 6/23 - Published: 4/18
RWBY:Psion Unleashed by EliteOp reviews
The Volunteer was considered KIA aboard the mothership, his lifesigns disappearing. Noone knows where he went but him. He needs to set up, find allies and enjoy his new life while he can, as dark things are coming.
Crossover - X-Com & RWBY - Rated: T - English - Romance/Humor - Chapters: 9 - Words: 11,031 - Reviews: 8 - Favs: 8 - Follows: 13 - Updated: 6/23 - Published: 6/9
Mass Effect: X-Com Theory: Project Shanxi by timedraven117 reviews
It has been over a century since the Ethereal Invasion and the Equis First Contact War. Humanity has learned to accept their former foes, and their former victims. But the threat has always remained, "The greater foe" promised by the UberEthereal. Now it is the year 2157, near the Shaanxi system the Relay War shall begin with a galactic order that has stood for over 2,000 years.
Crossover - X-Com & Mass Effect - Rated: T - English - Sci-Fi/Supernatural - Chapters: 9 - Words: 51,124 - Reviews: 46 - Favs: 143 - Follows: 176 - Updated: 6/16 - Published: 5/8 - Admiral Hackett, Councilor Tevos, Primarch Adrien Victus
War of Ages by Thunderbird013
A crossover between nearly a dozen different franchises! It's been over a year after the alien invasion and the Earth is now threatened by a new extra-terrestrial threat. To combat them, the X-Com project is put back into action and seeks help across dimensions. Again, not just a crossover with Metroid. I could put two franchises that were being crossed over.
Crossover - X-Com & Metroid - Rated: T - English - Adventure/Sci-Fi - Chapters: 1 - Words: 2,938 - Published: 6/9
X-com: The Kisaragi squad remake by BlackThief12 reviews
Is a remake dude. Check the god damn story for the user of Library of the damn.
Crossover - X-Com & Corpse Party - Rated: T - English - Sci-Fi/Supernatural - Chapters: 1 - Words: 1,523 - Reviews: 1 - Published: 4/16
Dust and Psionics by Malcho1234 reviews
[DISCONTINUED. Look for Vigilant for the rewrite.] Tossed in a new world... One full of strange enemies and even stranger humans... And yet, there is one thing that remains the same: Humanity is in danger. And Christopher Redmond had sworn to protect Humanity... Rated T because of XCOM
Crossover - X-Com & RWBY - Rated: T - English - Fantasy/Sci-Fi - Chapters: 6 - Words: 21,704 - Reviews: 53 - Favs: 98 - Follows: 115 - Updated: 4/15 - Published: 10/11/2014 - Ruby Rose, Weiss Schnee, Yang Xiao Long, OC - Complete
Vigilant by Malcho1234 reviews
He had sworn to protect Humanity... It was his mission. His purpose. Not even the high odds of his death managed to turn him away... And even though he is sent to another world Christopher Redmond will continue fighting and protecting Humanity. For that is what a soldier of XCOM does. Rewrite of Dust and Psionics.
Crossover - X-Com & RWBY - Rated: T - English - Sci-Fi/Adventure - Chapters: 1 - Words: 1,979 - Reviews: 12 - Favs: 53 - Follows: 88 - Published: 4/15 - Weiss Schnee, OC, Penny, General James Ironwood
Dehumanization by DasCheesenborgir reviews
He always had been more machine than man.
Crossover - Resident Evil & X-Com - Rated: T - English - Chapters: 1 - Words: 1,597 - Reviews: 1 - Follows: 1 - Published: 4/3 - HUNK
The Wakfu is out there by du911
Nox may have failed...but his legacy lives on...to completely screw over two universes! Inspired by Hotpoint and Psykotic Addiction!
Crossover - X-Com & Wakfu - Rated: T - English - Sci-Fi/Adventure - Chapters: 1 - Words: 433 - Published: 3/29
Fallout: Alien Activity by Sheepking
In which the apocalypse was the result of an alien invasion. Labelled In-Progress in case I ever feel like picking this back up.
Crossover - X-Com & Fallout - Rated: T - English - Chapters: 1 - Words: 288 - Published: 3/27
Adapt and Survive by nivlac reviews
It has been two weeks since Rolf Anderson sacrificed his life to save the earth, and during his funeral, a mysterious cloaked man took them and their base from the earth that they worked so hard to save. The base was put on a new, more hostile version of earth, full of mutants, slavers, radiation, and power armored soldiers with laser and plasma technology on par with their own.
Crossover - X-Com & Fallout - Rated: T - English - Tragedy/Mystery - Chapters: 2 - Words: 7,086 - Reviews: 15 - Favs: 19 - Follows: 27 - Updated: 3/7 - Published: 11/27/2014 - Lone Wanderer, Elder Lyons, Fawkes, Colonel Autumn
I Am Watchful I Am Necessary by TheConstellation reviews
Decades have past since the Ethereals threat was defeated and humanity has emerged united and stronger than ever for the conflict it faced. Now after discovering the Prothean Archives on Mars, humanity is about to end up on a much larger stage than it ever expected to play on when yet another alien threat comes knocking. And again, X-COM stands ready to fight. Vigilo Confido.
Crossover - X-Com & Mass Effect - Rated: T - English - Sci-Fi - Chapters: 9 - Words: 18,569 - Reviews: 359 - Favs: 726 - Follows: 999 - Updated: 2/25 - Published: 9/30/2013 - Admiral Hackett
72 | Page 1 .. Last Next »