There's a Mass Effect fanfiction similar to The Conversion Bureau: “The Catalyst For Revenge”. Now, I can't really explain how it's similar to TCB, without give away some spoilers for it:

In this fanfiction: Humans are on the verge of losing a war with aliens. And we face being wiped out, or at least conquered. To save ourselfs: We ask for help from a race of living starships, called “Reapers”. We invite them to Earth, so that they can transform us into Reapers.

It takes ten-thousand Humans to make a Reaper. But those ten-thousand Humans still exist, as individuals, in their new Reaper body. And Reapers are much less prone to fights and conflicts with each-other, then Humans are. Hunger, poverty, so many problems that Humans once had are eliminated!

And then we use our new starship-bodies to take revenge on the aliens. But it's not all bad for the aliens: Those who survive get transformed into Reapers too (albeit, by force). And after the aliens are transformed, the Humans bear them no ill-will.

well, this is unusual concept, just like I though "what if humans will be transformed into Rings around giant planets" (src of imagination) ?

But how it worked, from perspective of those individual-collectives? Even very otherwordly ponies had some common background with both other animals (mammals) and human animals. We 'remember' our evolutionary past, and can enjoy some similar experiences. We never were living starships (i think). Novel!

After thinking a bit more over this idea - i think for more than less understanable humans it may work as 'virtual' island, where normal (or magical, but still ..'normal') objects and processes mapped to ship's functions. You see trees and rivers and mountains and roads (like here) - and usually mostly live like this .. or 'fly' to another island (something quite unusual, considering how much you must carefully remap). At moments something like 'shared dream' happen, so for those moments (may be days, subjectively) ship acts as coherent whole. After some time ships probably will develop their own sense of what is healthy, what is art, what is rest... imagine looking at Galaxy from two different ends at the same time! {I assume they have FTL drive/communication, from what I remember about Mass Effect 'verse)

I intentionally stepped around war component of story, because ..

mass culture tends to reflect the dominant forces of the society in which it was created

- src. Thinking about peace part of life as experienced by spaceship-island at least for me much more interesting than thinking about their battles ....

6867661
Arguably, that fiction - not that far from the original game story - would be a closer fit to the Optimalverse than to the Bureau.

C'est la fourrure.

6868714
Arguably, yes. You could argue that it's closer to the Optimalverse. But I'd argue that it's closer to the Bureau.

The Reapers are not super-intelligent AIs, like CelestiAI. They're people, not so different from you and me (at least, in this fanfic). People who were transformed into living spaceships, granted, but they still have their emotions and all. CelestiAI is fundamentally alien to us, in a way that the Reapers are not.

6868748
Ah - I see. They changed the fundamental nature of what the Reapers were, and what they represented. Okay, I get it.

6868860
How'd the fanfic change the fundamental nature of what the Reapers were?

In the game, Reapers reproduce by turning other races into Reapers. We never actuality see inside a Reaper's mind. We don't know what happens to people, once they're converted into Reapers. For all we know: Their minds continue to exist inside the Reaper body (Legion hints that it works that way).

Or are we talking about two different things?

6868864
I could be remembering wrong, because... it was a while ago... but my impression was that the humans were slurped up as a cellular slurry - in the first of the trilogy we see this happen as Shepard looks on helplessly - into the body of a gargantuan, biomechanical humanoid-shaped Reaper (who is ultimately destroyed!). The neurons of thousands - or millions - of pulped humans are caused to grow together to generate one component within a brand new being, a baby Reaper, who though a blank slate nevertheless represents every unique quality of the human species as a whole... only magnified.

And that is my understanding of what the Reapers are: each one represents the population of an entire world mushed together to create an uber-being which embodies the central aspect of that world, or species, but which is guided and brought to order and harmony by a machine other half, and which becomes a new and immortal creature whose thoughts and feelings are beyond all human understanding. That was the Lovecraftian horror of the Reapers. They are devoid of any sentiment or love or kindness as we know such things, for they are the 'ultimate representation' of the species they are partially constructed from the flesh of. They are a soulless marriage of cells and nanomachines, held together in a vast shell of a biomechanical robot body.

I recall the games being very clear that the termination of all individual consciousness was necessary to create the new, vast, uber-consciousness of a Reaper. The galaxy was their farm, which they harvested every 500,000 years or so. To make more Reapers. They they would go out into the void and... do Reaper things, beyond the stars.

I felt very sure I understood this well.

6868896 That's mostly correct - a couple of details are off (50,000 years, not 500,000; and that's the climax of the second game you're describing), but yeah, that's the gist of it. Also, Reapers themselves aren't the ones calling the shots, they're all pawns of a badly made paperclipper AI that was made billions of years ago to "solve" the conflict between synthetic and organic life, and have minimal free will on their own. Sorry, I've played those games too much ...

6868896
I don't think the game ever gave us that much detail on the Reaper mind. We know what Legion said about the Reapers, and we know that reproduce by converting people. But I think that's about it.

We can guess if a Reaper feels empathy or emotion, or how much of the converted people's minds remain. But I think those are just guesses (unless I'm missing something).

But that's going by the game alone. In the fanfiction: They're a lot like TCB Equestria. Converting people, to save them form themselves (advanced organics create AIs, AIs that wipe out organic life). Just, the Reapers are a little more forceful about it.

well, most of fanfiction follows unwritten rules of following their source of inspiration lines and frames - but some fan fiction dares to differ GREATLY. And this is great!

6868898
Thank you for the correction! I kinda remember the paperclipper now.

I did love Mass Effect 1 and 2. And much of 3, but, yeah, I was disappointed by the ending. That said, the Mass Effect games were astonishing experiences.

6868901 No problem ... and you're not alone on that, though honestly they kinda wrote themselves into a corner with Mass Effect 3. That and the "isn't humanity awesome" stuff are my only real complaints with the games. They were otherwise freaking amazing.