Well they are just physical embodiments of concepts, do they really need a set physical form?

I’m pretty sure the Elements do different things depending on the inner state of whoever they’re used on – and, referencing a certain individual in this comic, that they can be forced to act outside of the context they were meant to be used in, although this can have consequences similar to randomly corrupting the memory of an early personal computer: garbage displayed on the screen, loud repeated strings of speaker noises, hard disk corruption, the wearer turning into a raging she-demon…
 
I was going to say that the Elements can probably kill sufficiently-far-gone adversaries, but it was the Crystal Heart that offed Sombra, wasn’t it? Different culture, different magical ‘technology’, different range of potential behaviors…

You guys are cynical as hell.

Ah, the good old Elements of Macguffin:  
Random! (Pinkie)  
Genericness! (Applejack)  
Flashiness! (Rainbow)  
Casual acceptance of their importance! (Fluttershy)  
Mineral Macguffins! (Rarity)
 
And the final element that binds them…
 
Contrived power levels!! (Twilight)

@Background Pony #87FC  
I believe the implication may be that their vulnerable magic tree-ness directly contradicts their original indomitable heart and soul-ness.

@Background Pony #1957  
So far, pretty much the only “definition” we’ve had of the Elements of Harmony, aside from their interconnectedness and the fact they came from a magic tree, has been through the effects they’ve caused. So what you’re saying is that they shouldn’t have been used at all?

@Zennistrad  
Then you leave it undefined,  
@Background Pony #F5FF  
See, this guy knows what’s up.

People will happily suspend disbelief for all sorts of things. Its when the rules start changing on the audience that it starts to break down.

@Zennistrad  
And now we may never know just what their deal is.
 
Which kind of sucks, but whatever.

@Background Pony #1957
 
The Elements of Harmony have never been defined, even in the first episode they did something completely different against Nightmare Moon from when they were first used.

@Background Pony #F5FF  
You either define it, or leave it undefined; you don’t continually re-define it.

Yeah, pretty much.

How else do you write an undefined, super powerful force of stuff?

How else do you write an undefined, super powerful force of stuff?