I suppose this could explain how Nightmare Moon in her rage was so much stronger than Celestia.

To be fair the comic state sombra has been lied for his lifetime, tortured for a day every year, and being forced to betray his only friend, he get a right to get very pissed off  
But comic isn’t confirmed canon, what do I know?

This just SPOON-FEEDS my theory that MLP is turning unto DBZ

She said her magic gets stronger when she’s more emotional. That means every unicorn’s magic have their own boosts for own conditions.

Celestia’s emotional control is Mom-tier.

@neo4812  
It’s pretty bullshyay.

@Necrikus  
right? all you can do is edit it but if you wait 5 min you can’t edit it anymore

@Necrikus  
Oh crap. I accidentally replied to the wrong comment and I don’t know how to undo it.

@klystron2010  
>comparing My Little Pony to Steven Universe  
Excuse me. I need to go kill myself.

@klystron2010  
It doesn’t have to. One can easily dig up or make rule sets for point-based or cool-down based spell casting and apply it to MLP easily.

Maybe that’s why Celestia jobs so much. She finds it hard to get close to her emotions.

Explains why Steven Universe has so many powers.

@Necrikus  
As far as MLP goes, vancian magic don’t apply.

Maybe that’s not universal. She is probably a sorcerer so she uses her Charisma score for magic. Celestia may have her spell casting keyed to Wisdom or Intelligence.

so its like the force?

@moonlightaveger  
I think she’d take a bit more direct approach.

Actually, Glimmy stated that her magic is tied to her emotions, not all magic.

@docarrol  
Not really. Suppose Celestia can do that and takes away the light from some country that is giving Equestria grief. All she’d really get from it is other nations sympathizing with her enemy, sanctions and one hell of a drop in public opinion. I’m not convinced Celestia can pull this off without harming her nation as much as her enemy.
 
This is also because I don’t think that Celestia is that powerful inside Equestria to be able to muster the popular support to keep in power if she tries to pull that off. Even if she can convince the general equestrian population that “it’s necessary”, I’m sure the nobility has business with outside interests.
 
But this is going WAY off topic, I think.

@moonlightaveger  
Well, she does control the physical movement of the sun; and the moon, while Luna was away. It’s been speculated in some of the fanfic that they can direct one or both to simply not rise and/or shine on other countries. That would be a heck of a “political and diplomatic” disincentive.

@Background Pony #4AAB  
I understand where you’re coming from. I just don’t see Celestia as particularly powerful in that sense. I think that her “power” is likely more political and diplomatic than raw magic might.

@moonlightaveger  
She defended an entire nation by herself for over a thousand years.  
Though i do hope we get to see her kick some ass at some point

@Pony_Joe  
clearly not

@Background Pony #3822  
Think that is generalized as all ponies having connections to emotion and magic.
 
Friendship is magic after all.

That may explain Twilight’s inaccuracies in her holographic simulation

No no. Starlight said that her magic is tied to her emotions. Other ponies’ magic? We don’t know.  
What I see is this: Twilight’s magic is probably tied to her emotional state, Starlight is tied to her emotional level.
 
How is that different? Twilight’s magic depends on whether she’s angry, happy or excited. Starlight’s magic depends on whether she’s mildly annoyed, very annoyed or triggered.  
I’m wondering if this is a setup for Starlight’s eventual triggering and her finally achieving ‘Princess Form’ without becoming an alicorn herself. She’d probably be the first Unicorn Princess.