The Reaper invasion is nigh. Outnumbered and outgunned, the Citadel must turn to two new, dangerous allies for salvation: the Adeptus Mechanicus and Imperium of Man.

A battle against the forces of Chaos strands a Necron lord in the galaxy of Mass Effect. With what's left of his dynasty under his banner, Veronakh Lord of Solvatakh intends to lead his people to glorious conquest. Can Commander Shepard stop the Collectors and curtail the ambitions of the Necrons?

Lustria is destroyed, the lizardmen departed for the stars. Finding an ancient gateway, what will the children of the Old Ones find on the other side?

A fleet of Imperial reinforcements, Mechanicus detachment and a chapter of White Eagles meant for Cadian sector are swallowed in the unruly sea that is Warp. They emerge into a new universe, one without the Emperor, their faith strong, they will see this galaxy conquered.

One of the oldest living perpetuals along with the remains of an inquisitorial retinue are transported into an alternative past where aliens are not simply foes to slay but friends and allies to mankind. For the perpetual it's a nice change of pace for the others? Well they may learn that co-existence might not be such a bad thing after all... Rated M for obvious reasons.

Some destinies are written out centuries, or even millennia, ahead of time. However, when destiny is derailed, new plans have to be implemented. Sometimes, that involves ripping someone away from the peaceful end they seek and thrusting them into a tide of never-ending war in order to fix what can never be repaired.

A very different Mass Effect galaxy encounters a strange and relentless invader that is on constant hunger for Biomass but they never know it's just a glimpse of what coming for them. Featuring: alternative history for every species, a bigger and more populated galaxy, cunning Asari, militarized and germanized human empire.

Jesse Shepard was a lot of things: A solider with a shady past, a son, and a brother With the threat of the Saren and the Reapers hanging over his head, he discovers a secret that will shake not only the foundations of the Alliance but the galactic community as a whole. Meanwhile on the Citadel, stalks the lower wards leaving Caroline Shepard and her new very strange partner to fi

Even as the Great Crusade took place, the Emperor in His great wisdom had contigency plans in the event that his Imperium was destroyed. Seeds to sow a new Imperium if the first was to fall. This is the story of one such seed with Rogue Trader Shepard at the helm.

Stuck in a more peaceful galaxy, the Tau of the Farsight Enclave must still prepare themselves for war against the forces that conspire to destroy it. But as they fight for their existence, elements from their old home come to strengthen their power in said old home.

Astartes Shepard has been assigned a new task: to escort strange alien civilians to a site within Imperium borders. The Emperor Renewed has issued a personal directive that preparations are to take place, an alien race seeks to destroy the peace achieved within the Imperium's holy borders. My first foray into the 40k 'verse, insight would be helpful.

Everyone's favorite technophilic groups meet: the Adeptus Mechanicus from Warhammer 40k and the Quarians from Mass Effect. When the Cult Mechanicus learns of the existence of the A.I.'s known as the Geth and Reapers, they decide only one thing can be done, and enlist the help of Quarians to fight once more for their ancestral home. Keelah se'lai and Glory to the Machine God!

A joke of Chaos daemon sent two unlikely allies - an Eldar Farseer and an Imperial Storm trooper, through the Warp and into another Universe. In this place, everything is alien to them. Except for one thing - war. War is something they know very well. (Story adopted by Regina Dea. New author starts from Chapter 21)

A unique Iron Warrior Sorcerer finds himself within Mass Effect, in this new reality, there is no chaos to twist the hearts and minds of weak men. Jane Shepard, the Butcher of Torfan, a woman of iron heart, soul, and mind, she needs to be if she intends to save the galaxy from the Reapers, it is a cause she will do almost anything for. No deed is too cruel, no sacrifice is too much

When fighting against Tyranids on a far flung Civilized World, Primaris Space Marine Marcus Tyrellus expects it to be like every other day in the Imperium of Man. Little does he know is that, he, and a few others, will soon be working to save another universe from destruction at the hands of an ancient foe.

The Tomb Kings are victorious. The world is theirs and Chaos is banished from their world. Now they turn to the stars to claim everything in the name of the Imperisable.

A half-Eldar, hidden secret of her father, a goddess of healing that does not know how to fight, a simple Seer and her best friend Howling Banshee got the one way ticket to fell into the ME Universe. Of course to add problems to their opportunity of new life, the Reapers are coming to cleanse this universe of every sentient being. What to do? What to do indeed?

Jane stared at him, confusion crawling into her expression, but she thought back to how many times Soter astonished her, she thought about Astartes and psychic power and the cruellest regime imaginable, and she thought about the even crueller trans-human madmen that sieged it. She thought about Soter the Space Marine, Soter the Iron Warrior... "Okay. Do it." One-shot in Iron Effect

A plot to throw the galaxy into chaos and only those outside the rules were a match for it. Rated T for violence, death, and profanity.

To them? the fact that they were entirely thrown into a new battlefield was entirely amusing. Next chapter will be delayed. Rated T for violence, death, and profanity.

Cerberus research labs look at all sorts of things. Some they probably shouldn't.

In an unexpected and highly unlikely turn of events, a catastrophic warp breach from a crippled ship manages to fling a Rogue Trader - or rather, the youngest son of a Rogue Trader - through time and space to a universe quite unlike what anyone on-board in used to. They make the best of the situation.