Curious on who would Luna be if Celestia is The Boss here :0

“Look at this scar… This is proof that I was once a mother… I gave up my body and my child for my country… There is nothing left inside me now… Nothing at all… No hatred, not even regret… And yet sometimes at night, I can still feel the pain creeping up inside me… slithering through my body, like a snake… I’ve never talked this much about myself before… Thanks… Thanks for listening to me… I feel content… Snake…  
Commence the operation.  
I raised you… I loved you… I’ve given you spells, taught you techniques, endowed you with knowledge… There is nothing more for me to give you… All that’s left for you to take… is my life, by your own hoof… One must die, and one must live… No victory, no defeat… The survivor will carry on the fight… It is our destiny… The one who survives will inherit the title of Princess, and the one who inherits the title of Princess will face an existence of endless battle… I’ll give you ten minutes. In ten minutes, MiGs will come and bomb the hell out of this place. If you can beat me in less than ten minutes, you’ll be able to escape in time. Let’s make this the greatest ten minutes of our lives, Twilight…”  
“Princess…”  
“You’re a soldier! Finish your mission! Prove your loyalty! Face me!

I’d prefer this over what actually happened. It’d spare us a terrible song.

What a thrill, with darkness and silence through the night…

Celestia went to space and saw the world as it truly is.

“Just finish me Twilight”

JP VA for Celestia voiced The Boss in MGS3 JP Dub.  
This pic is canon

Celestia: This is your final test. Do you have what it takes.
 
Twilight: What ‘what’ takes?
 
Celestia: To ascend. _{Ethereal blades shimmer into existence around the white mares head.}
 
Twilight: To ascend? Ascend to what? Where?
 
Celestia: My most faithful student. Your journey to this moment has been a glorious success. However you ascend today, will be dependent on whether or not you can put all that you learned into action. This day, you will ascend.
 
Twilight: What do you mean by that Princess.
 
Celestia: Dear Twilight, you do not need to call me that anymore. _{A wicked sneer runs across her lips.} As I was going to state, my student. However you ascend will depend on whether or not you remain standing, or I.
 
Twilight: But Prin- _{Her words were cut off as both ethereal blades slashed down either side of her body, narrowly missing by mere centimeters. Her mentors once serene demeanor was replaced by one of malcontent.}

For some reason this made me think of Looper