The Return of Nightmare Moon

Celestia stood in the throne room of the castle. She knew her 'sister' would show up. She told the guards to leave the palace and protect the citizens. Sure enough, Nightmare Moon showed up.

"Hello, sister," she said in a sly tone.

"You are no sister of mine!" Celestia shot back at the mare that had just flown in through the window, smashing it in the process. "You're a monster."

Nightmare Moon just laughed. "I'm a monster?" She yelled, her voice echoing around the room. "You were the one who trapped me in the moon for a thousand years!"

"It was your fault I did that." Celestia sounded like she had just remembered something she wanted to forget.

Nightmare ignored her. "Well, my dear sister," she said in a tone of fake sweetness. "I'm just here to return the favor. As I was trapped in the moon and I raise the moon, I think it's only fair that, as you raise the sun, you get trapped in the sun!"

Celestia scoffed. "The sun's a ball of gas. I can't be trapped in it."

"Exactly. You'll die the second I send you there." She turned to face the broken window. "Here, Twilight."

A purple alicorn with bright red eyes flew in, smashing even more of the glass as she did.

"What is your wish, master?" She said, as if in a trance. Oh, wait...

"What have you done to her?!" Celestia screamed, stepping forward.

"Twilight, stop her from moving."

Twilight then fired a bolt of magic at the princess of the sun. Celestia, now with a purple glow around her, could move nothing but her face.

"You won't get away with this, Nightmare!"

Nightmare Moon laughed again. "Oh, but Celestia," she paused and grinned. "I. Already. Have."

She shot her own bolt of magic at Celestia, who vanished instantly. The mare of darkness laughed for a third time, stopped, told Twilight to join in, and then continued.

"Equestria is mine. All mine." Her face went darker. "All mine to destroy!" She then realised Twilight was still doing an 'evil' laugh. It sounded like a robot having a heart attack. Nightmare turned to her and said. "You were a good help Twilight," she paused, "but you are no longer needed. Say hello to my sister for me!" She shot at Twilight, making her disappear too. "Now, back to Equestria..."