Sacrifices

Twilight never expected the Elements of Harmony to kill Nightmare Moon. She also never expected to have to ask Celestia why.

When Twilight and her friends used the Elements of Harmony on Nightmare Moon, she expected them to purify her or put her back on the moon. Instead they killed her. Haunted by the fact she took a life, Twilight goes to Princess Celestia to find out if she knew the Elements would kill her sister. And if she did… why did she let Twilight do it?