@redweasel  
Again, they mean Twilight in particular. If she, say, took all the Alicorn Magic like in the S4 finale, then built on it, that go a long way towards Almightiness.

there’s no other way to kill the almighty alicorn
 
except celestia, and luna they’re both dead.
 
oh also cadance. yep, alicorns just dying left and right here.

@Darth Sonic  
That could be the case.
 
Though, now that I think about it, my reaction here isn’t so much a question as to how Twi got so powerful. It’s really more a result of the emotional themeing doing a complete 180. The whole Royal Sister burial scene portrayed Twilight as very vulnerable, quite possibly with no more life left in her than her very normal (non-Alicorn) friends. Over the next few pages she goes from that to a cold-hearted tyrant, who many consider nigh indestructible. Even if that transition took several thousands of years, the short time taken in the comic to explain it makes me wonder if we won’t see her status shift radically again. And that’s kinda straining my ability to take this information as it comes…
 
@armadiloeater  
That’s a possibility. Although we are diving pretty hard into the realm of things not said in the comic.
 
And, if you think about it, would Tia’s and Luna’s powers be as strong as they had been during Tirek’s invasion? I mean, since the Royal Sisters are gone, it’s not unreasonable to assume that their strength/magic power was waning as their time wound down (and so Twi would be left with little of what they had). If that wasn’t the case, then it would mean that two exceptionally powerful beings who had survived nearly a thousand years couldn’t continue living even though they had all that power still in them. And that would make me question whether that power was something that would really make Twi more resilient.

@Exedrus  
Well, what if Twilight absorbed their powers when the both of them died, just like in the episode? She seemed pretty durable then, being thrown through mountains, blasted, crushed and clothlined by a giant demon centaur, before getting away without a scratch. What’s more Tirek had absorbed every other pony’s magic.
 
So even if you only take canon facts, we know that the power of the alicorns combined can match magic from the whole population of Equestria. Seems worthy of the title “Almighty” to me.

@Exedrus  
Again, I repeat my point: I think it’s the Twilight in Alicorn Princess Twilight that got her the “indestructible” moniker.

@Background Pony #A069  
And it is kinda weird that Spike seems to think Alicorn Twilight is so indestructible considering we were burying Luna and Celestia ~10 pages ago…

@Background Pony #A069  
Twilight became far more powerful then the other Alicorns. There simple. No “weird interpretations of the Alicorns” needed. Just good ol’ fashioned OP Twilight.

“There’s no other way to kill the almighty Alicorn”
 
Wha? I understand this is all personal canon and all, but some people have very strange ideas about them.  
I dunno, maybe its just me but from everything we’ve seen they don’t seem “almighty” at all. Which I think its fine and actually makes things more interesting/balanced. I’ve always seen them as the pinnacle of the Pony race sure, but from that to almighty…hell, Discord aside (for obvious reasons), a fully-charged Tirek or Chrysalis, as well as an angry Ursa, Dragon or Hydra would most likely put them on the spot and have a good chance at killing them.

Oh sheeeet

Sweet mother of Celestia that’s dark. I guess friendship isn’t that magical after all…
 
(Although some feeling inside is telling me that this will have a happy ending one way or another.)

Why kill her? Just rainnuke the castle, dig Twi out of ruins and beat her up until she turns good again (provided it is still she and not some Changeling Queen in disguise)! “Almighty alicorn” she may be, but against 5 other Elements (who is badasses in their own rights) together she won’t stand a single chance!

You know, that prophecy didn’t specify which friends Twilight would outlive.
 
Did Twilight just have no other friends and never bothered to make any more?
 
Hell, Spike’s still alive, and given the very loose wording and definition of friend, I’m sure Discord’s fine, too.

Kinda funny how the prophecy only said Twilight wouldn’t outlive her friends and they assume that means Twilight will die before them.
 
I can think of at least three different interpretations of those six words and they only got one.
 
…I’m pretty sure the Doctor’s plan on saving everyone is going to hinge upon that.

@Pagan  
Ya, this page makes it pretty obvious she’s been replaced.  
Too obvious.  
I’m waiting for the twist.
 
@PonyPon  
The prophecy says “will not outlive”, I don’t see how it could mean anything else than “die before them”. I thought it could mean that she would change so much that old Twilight was effectively dead, so maybe the prophecy already came true.

@PonyPon
 
@armadiloeater
 
The prophecy actually states “Twilight will not outlive her friends”.

welp lets go out and kill that crazy bitch

@armadiloeater  
It might just mean she has to die in their presence.
 
‘Before’ has more than one meaning.

@Background Pony #2C54
 
Coming to think about it, what happened to Discord?

Da Fuq?
 
They are countless beings into the Equine World who can kill an Alicorn.  
I mean Tirek or Discord for example. Or other powerful beings that held in tartarus.

Don’t be hard on yourselves it’s not even Twilight.

Wait… He’ counting on them helping accomplish a prophecy… That states that Twilight will die before her friends… Is the rebellion going to kill them one by one until the prophecy triggers?  
I guess not, but it would be logical.