A full codex dedicated to the characters, cultures, places, objects, times, etc., related to the Concordian Cycle starting from Book One: Dawn of a New Age. Will be constantly updated alongside the books to fit with the details of the series. Please read the series first if you wish to gain a greater understanding. On Hiatus

SPARTAN-A073 and B158 are thrown into the Mass Effect universe after a freak slip-space accident. They're mysterious and shady outcasts, keeping to themselves. This might be normal to them, but to the Shepard's crew, they're unknown variables. (REWRITE: ISOLATION). DISCONTINUED, ALRIGHT?

Escaping in the Normandy, Shepard and her crew was hit by the shockwave and somehow flung through space and time into another dimension entirely. They end up in 2551 and crash land on a planet under attack by Covenant forces. OC crew member involved. Alternative Universe story.

A aged old man tells his grand daughter about the legendary Spartan that is Commander Shepard. Part 1 of 8 of the Man Of War Series. Prologue of the series.

"I swear to protect Earth and her colonies."That is an oath made by 75 children,75 children that were trained to serve Earth by becoming the best soldiers know in the history,and even throught that Master chief,AKA Spartan 117 is not in the same Universe anymore,he intend to fulfill this oath that he made so many years ago...No matter the price for it.

The Mass Effect and Halo universes embark on their first real mission together...but they have to make it through the debriefing first.o

The year is 2551. The Initiative is scattered across the galaxy, trapped between a desperate UNSC and a near-victorious Covenant; the same alien alliance which seeks to dominate or destroy any new species it encounters. Sara Ryder, though but a young woman, cannot afford to falter once the fate of 100,000 innocent lives is thrust upon her shoulders.

Join Commander Ashley Shepard and Noble Six as they fight the Covenant with support of the Alliance and Turian forces.

A lone Spartan III finds himself on Horizon in the middle of a Collector attack. He finds and joins Commander Lillian Shepard and joins the fight against the Collectors and later the Reapers. He finds friends and more along his journey (FShep and Liara) (OC and Kasumi)

What would happen if the Covenant never existed? What would happen if first contact was the Council and the UNSC?

"He had never been defeated in battle. He had never failed at any task, no matter what the challenge. He was never wrong. The Imperial Admiral's only flaw was that he had been so revered, some said even more so than any Prophet. For the sin he had been exiled to the fringe worlds of the vast Covenant Empire."

The Reapers are dead, Cerberus is defeated and a new peace rains over the galaxy but Shepard know's this is not the end. Before he planned to destroy the Reapers the star boy spoke to him about an impending doom that will fall upon the galaxy and will stop at nothing until all sentient life will be consumed by the endless horde that will feast upon their bones.

A Turian patrol makes hostile first contact with the covenant during the height of the human covenant war. Will the council be able to stand up to the might of the covenant war machine? Will the UNSC be able to trust another group of aliens so similar to their hated foe. How will the specters react when they learn their not the best in the galaxy anymore.

The primordial became part of the flood but it did not simply become part of the gravemind no instead it watched over the war and when the halos rings fired it took over and set events in motion that would forever change the fate of another galaxy

A Series one-shots ideas where we laugh at the misfortune of the Citadel Council and its associates when trying to use Forerunner Technology not counting that is possible incompatibilities, Power Consumption and other dilemmas we neglect when it comes down in other stories with the Mass Effect Technology. This story will be updated as Ideas start Coming Everyone is Welcome Aboard!

During the events of Mass Effect 2, Commander Shepard discovers a SPARTAN super soldier stranded in the far reaches of the galaxy. Befriending this new ally, she embarks on her mission to shut down the collectors. During her mission she uncovers a dark truth about the reapers and the galaxies of the universe.

Años 2552 después de la guerra contra la Insurrección se descubrió un objeto alienígena ene sistema Shanxi que cambiaria la forma en que la humanidad vería en universo

While Suffering writers block I have decided to flush out the many technologies and ideas I have had about the universes I am writing, I hope this paints a better picture of my crossover universe. Thank you all for the support you have given me. Included will be weapons and technology involved in the various universes as well as historical records.

En lo profundo del vacío un antiguo ser observa cómo los eventos transcurren en los infinitos universos más en uno en concreto se centró dado que en él las creaciones de sus creaciones mataban a sus padres por la traición de sus hermanos mayores que engañaron a sus hermanos menores para facilitar la destrucción de sus padres mintiéndoles sobre cómo sus padres planeaban aniquilarlos

In 2554 the UNSC made contact with the Citadel races. But not everyone wants peace. Is cooperation between the UNSC and Citadel possible against the ex-Covenant splinter factions or will it turn into a three way war. ODST Lt Colonel John Shepard and Spartan Fireteam Crimson is right in the middle of it.

AU story of a squad of Combat Applications Group operators being sucked into the stargate made by Precursors. Can they make it back or will the bring the might of the UNSC.

Codex of an alternate history of the UNSC by 2897

Megaverse. A grand vision, on how Mass Effect, and others will be affected by a humanity forged from the influences of 1980's-2000's Sci-Fi and such. Prepare for BattleMech's, Powered Armour's, Fusion, Energy Weapons, Psychics, Magics, and more. How will the Citadel deal with a humanity that has seen and has Cyborgs, Super-Soldiers, BattleMech's, WarShips, with more to come?

Supreme Commander Thresk'Talamee is exploring an anomaly picked up by a probe, what he finds could change the course of the covenant and the war with Humanity. Admiral Jaehart Irilan is leading an exploration event to find colonies for the Salarian Union. Till he finds a probe from an unknown species, what will happen now? Rated T for violence and graphic depictions of death.

Fourth Generation Spartan Lucas Ryker is the Spartan without a team, preferring to shirk his fellow Spartans because they'd only "slow him down." However, when he's forced into cryo sleep during a mission to find the missing Master Chief due to extensive damage to the ship's life support, he'll wake up to a galaxy changed and realize working solo won't work this time.