Possible title: six friends, two new princesses.
Tags: drama, sad

My idea comes from the OP for Season 2, and was to be a mid-season Series End.
Basically, the two Princesses were seriously injured by Discord playing yoyo with the sun and moon, but it didn't show for months. Meanwhile, the Elements are messing with their Bearers: first they disappeared from their Vault and appeared on them (and couldn't be removed for longer than a hair-brushing), then reshaping themselves (Generosity becoming a tiara and Laughter and Honesty becoming sets of four horse boots each) and slowly reshaping the bearers (horns and wings growing, and Pinkie and Applejack growing altogether), and finally the Elements beginning to draw the Bearers physically and mentally closer together into two trios: Twilight, Applejack and Dash, and Rarity, Fluttershy and Pinkie.
Of course, as this story would be a drama, the girls chaff at the loss of privacy and independence, but also try to adapt: Dash has to quit as weather manager and has to downgrade to part-time weathermare, so she, Applejack and Twilight can spend the day alternating between working together the farm in the morning, then moving to the market so Applejack can sell while Twilight part-times the library and Rainbow part-times with weather work (even if she has to remain within a kilometre of the other two). They then return the cart back to the farm and choose whether to sleep in the farm or the library. Rarity, Fluttershy and Pinkie would thus need something similar.

Prologue:
Celestia and Luna speak about the situation, and agree that their time is up, and won't be able to keep it togeyher for more than a few months.

First chapter:
The story would then start months into the situation, with Twilight waking up sandwiched between Rainbow and Applejack and feeling annoyed that they all had, once again, sleep-walked into a single bed. They go through their day hating their leash but not taking it out on each others. Chapter ends as a Royal Guard delivers them an urgent summon to Canterlot.

Second chapter:
The six girls are rushed through the streets of Canterlot and through the castle, to end up not in the throne room, but the royal apartments. They arrive to see Celestia in bed, who has just enough time to say her last bit of encouragement to Twilight and expire... followed by her exploding into the corpses of three ponies.

And I didn't flesh out what follows, but it would have been about the Mane Six fusing into two alicorns and taking up their mantle.

4975852 So... more or less my idea 3# ?

I'm for that !

Edit: Does it have 2 be T.S. + R.D. + A.J. & Rar + F.S. + P.P. ? "( Fusions 1 )"
I would make it T.S. + F.S. + A.J. & Rar + R.D. + P.P. "( Fusions 2 )"

I'm second choice would be T.S. + R.D. + P.P. & Rar + F.S. + A.J. then yours "( Fusions 3 )"
Rar + R.D. + A.J. & T.S. + F.S. + P.P. That one mite be funny "( Fusions 4 )"
f.y.i. If I would make this story, I would make it into a some-what pick your on story tip of story. Pick your own Fusion.

P.S. We shod also do a Prequel of this idea !

p.s. Shod we make the 2 know alicorn Lovers ?

I like it.

4975852 Had a very similar idea, but instead it was Celestia sneaking into each member of the Mane six's bedrooms and "Modifying" them, physically and some what mentally, so they can rule after she dies (Sombra left her a nice poisonous persent)

Your idea is good though......

4975982 But wouldn't it be Luna who would be doing some-thing like that ? She is the princess of night/dream

p.s. What would she be Modifying ? and which Fusions/combination would you have picked ?

4976011 No fusion........ which is why I didn't bother posting the idea in a forum

As for what was modified........... added muscle, removal of most fat in their bodies (not their breasts for obvious reasons).
As for mental, only a couple things, (IE Increasing all of their IQs, make Fluttershy more outgoing, ETC)

4976052 Wait, was that... That WAS by you !!

p.s. In this idea that 4975852 & I had, which Fusions/combination would you have picked ?

4976062 yes, yes it was......

And to answer your question
+ + & + +

4976065 the 2 idea are different.

p.s. so.. Fusions 3, One being grand, the other being more down-to-earth
Why did you pick this one ?
Which one would be your second ?

4976067 A Twilight, RD & PP fusion seems more fitting for daytime ruler

Whereas a FS, AJ & Rarity fusion seems more fitting for the night (especially because of Flutterbat)

If I were to pick another..... + + & + +

And to answer another Question, I would have Alicorn lovers in my story......

4976078 ok, but A.J. is more of a day pony, not a night-pony

me: + + & + + "( Fusions 2 )" I think that would be a good balance, one tom-colt, one gentle, and one with... magic-powers?
I also see + + good for the day-paper-work that Celestia does, and I think F.S. & A.J. love the day more
and + + good for the dream-walking part of Luna's job and night-life

But that can't be one has 2 earth-pony, and the other has 2 pegasus.

Me 2 !

p.s. 4975982 What do you mean by "( Poisonous-Persent )" ?

4976098 Think what to Dumbledore in Half-Blood prince, basically it's a poison that spreads (slowly) throughout the entire body, before shutting all organs down at once...........

I like this one.

4976111 Oh...

p.s. What about the rest ? 4976098

4976133 Which one ?

this one>>4975852

4976404 Can you explain what you mean ? the Story idea, or the Fusions ?

4976567 both

4976649 ok, what is your second pick of the Fusions and why ?

4976662 I just like it that all.

4976717 K.

4975871
The way I shaped the trios was mostly to whom would work the best with Pinkie. Rarity might be an "interesting" choice to merge with Pinkie, but she wouldn't go bananas like Twilight; Rainbow would similarly go crazy, in contrast with Fluttershy rolling with the punches.

4980087

Why would Twilight go bananas ?
She is no monkey ? LL

Why would Rainbow go crazy ?
Doesn't she like Pinkie ?

Why would Fluttershy rolling with the punches ?
Wouldn't it slow Pinkie down ?

4980087 4976717 4976111 What shod the new princess shod be called ?

"( Fusions 1 )"
T.S. + R.D. + A.J. = Princess Rainbow-Sparkle-Jack ?
Rar + F.S. + P.P. = Princess Rari-Fluter-Pie ?

"( Fusions 2 )"
T.S. + F.S. + A.J. = Princess Apple-Sparkle-Shy ?
Rar + R.D. + P.P. = Princess Rari-Dash-Pie ?

"( Fusions 3 )"
T.S. + R.D. + P.P. = Princess Pink-Rainbow-Sparkle ?
Rar + F.S. + A.J. = Princess Rari-Shy-Apple ?

"( Fusions 4 )"
Rar + R.D. + A.J. = Princess Rar-Apple-Dash
T.S. + F.S. + P.P. = Princess Shy-Sparkle-Pie