Hey guys, it's been a while, but I've got a serious headcanon this time around.

While this is definitely not a new concept, I think that by comparing which elements we think went to which Princess, we can have an interesting discussion, so without further ado, my version!

Celestia: - Magic: As the 'leader' of sorts, and the eldest sister, it makes sense that she would claim the most powerful and unifying of the Elements.
- Generousity: Definitely one of Celestia's virtues, remember when she granted the Apple family their land?
- Kindness: She's a big ol' softy really.

Luna: - Honesty: Celestia is manipulative, there's no two ways about it, Luna is much more straightforward in her dealings.
- Laughter: Honestly, this could go to either, but Luna seems like more the type to cut loose and let her mane down. (Nightmare Night anypony?)
- Loyalty: Because it's more poignant for the Element of Loyalty to be the betrayer in my opinion.

So then, what Elements do you think the sisters had? And why? Let's get this discussion started!

2212022
Celestia: Loyalty (to the state), Generosity (to her subjects and close ones), Laughter (remember the Philomena incident? Or how the idea of the Mane 6 ruining the GGG made it her favorite year?).

Luna: (brutal) Honesty, Magic (more uses of it than Celestia), Kindness (deep down she's rather kind; the first thing she did after NMM was to ask for forgiveness).

You have to remember that, for Loyalty, Rainbow Dash wouldn't even fall to the temptation of joining the Shadowbolts when asked to and the way Discord corrupted her was by subjecting her to a sadistic choice of two things she was already loyal to. It was somewhat suggested in the IDW series Luna had no loyalty to the nightmare forces but instead fell prey to their notions about Celestia's betrayal.

2212089 Definitely makes sense, both sister's are quite virtuous, so there's probably an argument for either of them having any element.

But on your point about Rainbow Dash, it's also important to remember that the Elements themselves do not lend virtues, the virtues already exist, and since no two people are alike, even seemingly simple concepts as 'honesty' 'loyalty' and 'kindness' can take on infinite variation in how they are viewed, presented, and acted upon. Just because Rainbow Dash exemplified Loyalty in that way, it doesn't mean that any bearer would match her in executing their own ideals of 'loyalty'.

Well, that's just how I see it anyway.