Celestia watched in horror as the blue magic engulfed her sister. Her cries of agony echoed through the halls until where Luna once stood was a tall pony as dark as the night sky with no moon.  
“Luna…?” She ventured. “Are you there, Sister?”  
“Foolish one,” It spoke, like injecting her veins with ice. “You are far too late to help us.”  
It’s voice was deep and menacing. This was not her sister.  
The shadows of the moon filled the castle like a void, the only light came from the being’s eyes.  
“You stood by as we withered in your shadow.” It’s eyes peircing through her. “So now we say NO MORE!!”  
Celestia stumbled back as she hit the wall, her crown slipping and clattering to the ground.  
“If we cannot have more, WE SHALL TAKE IT ALL”  
It’s horn glowed with a menacing light. It was out for blood.
 
 
So I’ve made it like a tradition to draw Nightmare Moon as a test to see how far I’ve gotten. Now I did a little extra.