Who is stronger: Princess Luna or Princess Celestia?

[Brainstorm 4,112]

They're equally matched.

[EpicEnergy 23,222]

In the show, Daybreaker seems to be more powerful than Nightmare Moon in the one episode she appears in, so normally I would say that as a result, Celestia is more powerful than Luna. However, it is unlikely that Daybreaker will ever become a reality, and Nightmare Moon seems to be stronger than Celestia in the show. So, with that said, I have come to another conclusion:

Daybreaker > Nightmare Moon, Luna, Celestia

Nightmare Moon > Luna, Celestia

Celestia and Luna's evil alternate forms are stronger than themselves. This does not answer the question about whether Luna or Celestia is stronger, but it is worth considering regardless.

Anyways, to answer the question, I think that Celestia is stronger mentally because she never became Daybreaker while Luna became Nightmare Moon. As for their physical and magical strength, I think that Luna is the stronger one but I have nothing to back that up.

[Tom Gallagher 33,590]

I’d say they’re both equal.

[dead account 2,711]

Luna is a lot stronger. She has as much power as Nightmare Moon has. It's not like she gained an evil, mysterious power or so. No, it is her strength, she transformed entirely on her own. Celestia was only able to defeat her and imprison her in the moon with the help of the Elements of Harmony. And when Nightmare Moon returns, she easily made her "vanish", whatever exactly that means.

Luna really has a lot of mysterious things going on for her, mysterious powers. Just think about the Tantabus. Such an awesome character!

[ExplosionMare 18,067]

I'd have to go with Celestia since Luna was never successful at overpowering her sister (well, except that one time when Celestia fell down towards the elements, but perhaps that was staged).