While my present story is on hiatus awaiting the final episode of Hellsing Abridged (which should be any day now) I figured I would give this summary to a very large project that I have been planning for awhile.
So I have read quite a few MLP/40K crossovers and they all seem to either see Equestria destroyed, single characters from 40K finding peace in Equestria, and most of them involve shipping, to each their own with the latter.
But I have little piece of head-canon that says Equestria could not only survive in 40K but turn it on it's head.
The story would begin with a brief introduction to the 41st millennium, explaining the grim darkness in the far future and giving a brief introduction to the 8 primary factions (Imperium, Chaos, Tau, Ork, Eldar, Necron, Dark Eldar and Tyranids) but also explaining that there are still good people, they just get killed almost immediately, and then the prologue would introduce 6 characters who died in battle while demonstrating the elements of harmony.
If anyone wants to give their own spin on this, feel free cause I'm too booked to do more than this summary, but the 6 that I had in mind are an imperial guard private (who stood his ground after the commissar died and his squad bolted) as the element of loyalty.
A gretchin (who pilots a killa kan with a rokkit on it and suicide bombs a titan by flying into the barrel of its gun and exploding when shot) as the element of laughter. (he also has 4th wall awareness and can break physics just like Pinkie Pie)
A Dark Reaper as the element of honesty because he engages the enemy openly and the space marine that defeats him as the element of generosity because he refuses an order to destroy the Reaper's soul stone. (These two would later have an intense rivalry similar to Rainbow Dash and Applejack's)
The element of kindness would (yes really) be an ork nob who doesn't like killing civilians, especially children who he knows can grow up and actually be a challenge, and before you dismiss this, you should know that this ork takes his unorkyness the way an ork would, he doesn't understand that he's different, he doesn't know why, and he doesn't care, and he still follows the unwritten ork code, being a nob means that any smaller, runtier ork that doesn't obey him is gonna get it good, and anyone who insults him or calls him unorky is gonna get it bad, he would die defending human civilians from Blood Axes that planned to doctor their skulls to look like space marine skulls.
And finally, the element of magic would be an Eldar Farseer who foresaw that dying at the point that she does leads to the prosperity of the Eldar.
After the 6 of them die, their souls are claimed not by the warp, not by their own gods, but by the spirit of harmony, who explains that they must return to battle one day, but for now, must rest, and then learn, with no further explanation, she teleports them away.
We would then cut to Equestria where to everyone's surprise, the friendship map has called the main 6, the young 6, the pillars, the royal sisters, and the CMCs to the tree of harmony.
Once they arrive, the spirit of harmony appears before them and explains that Equestria will soon face a danger the likes of which they have never faced before, and to combat this threat, warriors familiar with it have been summoned to defend them, she also vaguely explains that they have known nothing but war and hatred their entire lives as a warning not to stress them, or to expect them to be open minded.
She then explains that three will need more time, but three are ready to begin.
With this, she disappears, and in her place are the Farseer, the guardsman, and the gretchin, the guardsman because he never faced a warp entity before and felt that he could trust it (because magic).
The Farseer because she saw clearly the destination of this path, though not the obstacles along the way (more on that later)
And the gretchin because he's Pinkie, don't question it.
Introductions would see Pinkie and the grot hit it off extremely well, the Farseer come off as snooty as the stereotype for her race, and the guardsman (who along with being a private is only a boy) being unsure of what to make of his situation as he can't see these xenos as the monsters he was raised to hate.
A cutaway would see that the Dark Reaper and the adeptus astartes are both in Sunset Shimmer's dimension, one believing that he is lost and the other believing that he has been received by the Emperor (who saved him from the daemon that tried to trick him) and chalks up the happy atmosphere to the Emperor no longer requiring his enternal vigilance and service.
And another cutaway would see the ork cutting down timberwolves in the Everfree forest.
From here, for the time being, the following chapters would be similar to the MLP series, short stories that see the misadventures of the three currently introduced characters adjusting to their new lives, the least struggling would be the gretchin, whose chapter would consist of kid friendly grot shenanigans (if their about to get out of hand, Pinkie intervenes)
The trying but failing character would be the guardsman, whose chapter would probably include the CMCs trying to find a place for him (as he never knew what he was capable of outside of war, this could lead to several possibilities)
And the character who isn't trying at all is the Farseer, whose self righteous arrogance reminds Twilight of her old self... at first.
She tries to explain to the Farseer that they get their power from the elements of harmony, and the magic of friendship, which the Farseer writes off as ridiculous.
Twilight tries to teach the impatient Farseer, who later decides to steal the elements and discover their secrets her way, but Starlight (who has been far less patient with the Eldar) intervenes and defeats her in a duel, and then explains how magic works in Equestria again, now that she has seen it.
The explanation is similar to the magic of the warp, only they primarily focus on using positive emotions rather than negative.
Having learned first hand that a unicorn unassisted by the elements is stronger than her, the Farseer relents and chooses to enroll at Twilight's school of friendship.
After this brief interval of filler, Fluttershy would be called by the map to the Everfree forest, where she would find an unoccupied cave, empty but for several gruesome trophies, the skulls of manticores and timberwolves, she even sees that the dead fire was lit and fed with the timberwolves broken bodies, and the manticores were cooked and eaten, she reacts as you think she would.
As she's running for her life, she hears screams for help, and traces them to a molting dragon who is cornered by four manticores in thick foliage, over which flys a roc.
Fluttershy tries to help the dragon by using her stare on the manticores, but when it starts to work on one, another flanks her and she ends up in the same trouble, but just when she thinks it's the end, she hears the simplest and yet most iconic battlecry in the 41st millennium. WAAAGH!
The battle ends with three manticores dead, the roc dead (from dakka) and the fourth manticore fleeing for its life, however, manticores are just as big as nobs and twice as heavy, and their stingers aren't for show, so the ork is badly hurt.
After the dragon finishes molting, he helps Fluttershy carry the greenskin to Ponyville for medical attention.
This would see more filler as the ork recuperates, he and the dragon hit it off rather well, while the guardsman and the Farseer try to convince everyone to kill it. (with obvious results)
Eventually, the Eldar and the guardsman try to assassinate the ork as he sleeps, but Princess Luna intervenes, sending them into his dream and transforming the two into foals and appearing to the nob as the ork of all orks, Ghazkull Mag Uruk Thrakka.
Ghazkull tells the nob to kill the two foals behind him, and the nob explains his abnormality to Ghazkull, and to the foals behind him.
Ghazkull then orders him to move aside so that he can kill them himself, the nob refuses, Ghazkull threatens him, and the nob gets excited at the thought of fighting Ghazkull.
At this point, Luna releases the two from her spell and lectures them for not trusting that the ork, like they, were chosen for a reason, she then leaves them in an awkward silence that is only broken by the orks grunts as he fights in his sleep.
Another filler arc sees the 4 go on map missions, the only ones I have thought up at this point involve the greenskins, the gretchin helping a pony win a derby race (by building a Wartrukk) and the ork ending up in a music contest only to see a guitarist walk out on his band because nopony likes their music, his bandmates refuse to give up and try to play without him and the ork immediately recognizes their music, Goff Rokk.
The nob then grabs a guitar and jumps on stage and actually syncs with the band of ponies, and when the song ends, though no one in the audience applauds, the competition's judges, Octavia, DJ-PON3, amd Fluttershy (who applied to keep an eye on the ork) approved because of how much they enjoyed what they played, even if their audience didn't.
I can go on and on with these filler ideas, but I'll stop here, when the whole gang comes together, they do so in Sunset's dimension, and it is revealed that while Celestia and Luna are simple school principals, the ruler of this world really IS the God Emperor of Mankind, who reveals the truth behind his mortal enemies, the dark gods.
He reveals the War in Heaven, but when the Farseer claims that was the birth of the dark gods, the Emperor disproves that, they existed long before... as the gods of Harmony.
When the War in Heaven tore apart the balance, Honesty became Khorne, Kindness became Nurgle, and Magic became Tzeench.
The balance would have been even, but for Loyalty, who split in two, his lighter half becoming Discord while his darker half became Malal.
The balance would truly end when the Eldar corrupted Laughter, who became Slaanesh, this action all but doomed the universe to darkness, but as the balance shifted once, it can shift again.
The last god of harmony, Generosity, who became the spirit of harmony, repaired the shattered spirit of the God Emperor, and has been building Equestria and it's races, to reclaim the universe, and save her siblings the way Twilight saved Luna when she became Nightmare Moon.
At this point, it is explained that the Emperor supports Harmony's ideals as he has only ever sought order, which is merely another name for harmony.
And for anyone who still thinks this could never work, I am seizing the opportunity to introduce human counterparts to Equestrian characters that haven't been introduced yet as the Emperor's new army, SciTwi's brother is a general in the new imperial guard, the yak prince (I forget his name) is a new Primarch, and Ember is leading the adeptus sororitus.
The battle plan is to start with the Tau, assisting Commander Farstrike in dethroning the Ethereal caste, next would be the Tau launching an all out invasion on Terra as a decoy so that the main 6 and their 40K counterparts and Farstrike can teleport to the throne room and use the elements of harmony to revive the Emperor while their allies hold off the Custodes.
Once that is settled, the Farseer would share her vision with the Craftworlds while some may be skeptical as she once was, there are those like Farseer Macha who would be capable of believing such things and help her convince the rest.
The next step would be this new triumvirate providing enough troops to assault the Craftworld of Cammorah, and then allow the imperium to know the location of every single necron tombworld so that they can get trigger happy with the Exterminatus button.
After this, the ork nob, who through rigorous combat would be growing, would be amassing a Waaagh with the intent of leading it out of the Eastern fringe of the galaxy where the Tyranids came from, having his dream battle with Ghazkull along the way. (he would be much bigger by that point)
This would see the majority of orks cutting off the Tyranids, and pushing into their territory.
The final stage would be the traitor legions, by this point, the sudden surge of order would begin to affect the dark gods... and Harmony, Harmony would be much more powerful than she's ever beem in MLP and she would to start speaking to those less corrupted, not Khorne Berserkers or such, but chaos space marines and cultists who regret what they've become, especially the Iron Warriors, Harmony would begin to turn them against the dark gods and the Emperor would pardon them, having learned of his own mistakes.
Eventually, the dark gods would involve their champions, the Primarchs of their personal legions, Angron, Fulgrim, Magnus, and Mortarion.
The battle would be fierce, but eventually, Twilight and her friends would use the elements of Harmony on the fallen Primarchs and their legions, but when it would seem that they had won, the weakened gods would take on mortal form, each one as powerful as the Emperor himself.
They would keep the main six from using the elements to defeat them, and the Emperor alone wouldn't be able to defeat them, however while harmony wouldn't be able to affect her siblings directly, she would be able to find and reassemble the shards of Kaia Mensha Khaine as she did with the Emperor's soul ten thousand years ago.
Their combined might was enough to hold them off long enough for the main 6 to use the elements of harmony and purify the dark gods the same way they purified Luna.
I'll leave the epilogue to your imagination, but this is the summary of what stands to 2-3 years worth of writing if not more on account of how big it is.
Other ideas I had included the humans and Equestrians being the reborn souls of the countless innocents who are slaughtered by the billions daily, while most of these souls would be nobodies, (Twilight being one of the psykers who was sacrificed to fuel the golden throne) the royal sisters would actually be reborn Primarchs, Celestia being Vulcan for all the reasons he gets called the Primarch of Friendship, and Luna being Konrad Kurze for all the reasons other writers ship them. (looking at you Black Knight, but again, to each their own)
There would be scenes involving Discord and other characters, other friendship missions, and several fight scenes in the second half.
That's all I got so far, I will be rolling this over in my head while I finish other products that I have promised to do first, but if someone wants to give this a spin themselves, by all means.
Until then, I shall await the final episode of Hellsing Abridged, so I can finish my current fanfic Hellsing 40,000 and move on to the next which has already been promised to MyFunVideos (read An Author's Rampage for context.)