"I expected this..." Celestia said softly, almost a whisper, in that moment of dramatic emphasis.

Then she planted all four legs, lowered her head as her wings spread to full extension, and matched bolt for bolt with a brilliant blast of sunlight that lanced out from her horn to meet Nightmare Moon's attack.

"You are not my sister!" she bellowed in the full force of the Royal Canterlot Voice, rage and power so shot through her voice that it made the ground tremble. "AND YOU WILL BE DESTROYED FOR THIS MOCKERY!"