L: "Yes. I did have a pupil. I took her under my wing during my reign as princess. A descendant of the mighty Equestrian General Tempest Shadow, Opaline showed enormous potential. As much latent magical ability as even Flurry Heart had."
S: "What happened to her?"
L: "Well, as I told you, Flurry's death caused magic in Equestria to become volatile. Strange, even. I didn't realize it at the time, but the magic of friendship that gave our nation's strength was slowly being polluted. It was slowly transforming into something… else. Opaline began to crave it. Hoard it. Over time, she began to see magic as her weapon, and Equestria as her birthright. I tried to stop her, but by the time I put all the pieces together, her strength had evolved beyond even me. And so, I did the only thing I could think of. I called upon the wisest, most powerful magic-user I knew: my old teacher Twilight Sparkle. With her remaining power, she sealed all magic in the crystals you now seek, draining Opaline's energy away. But it cost her. Twilight Sparkle faded from the mortal plane, like the rulers that came before her. Then… I was alone."
S: "Then Equestria…?"
L: "Equestria was safe, but broken. I couldn't hold our nation together. Not after Opaline's uprising. My reign was one catastrophic failure after another. First Flurry Heart, then Opaline, the self sacrifice of the TRUE Princess of Friendship… all a result of my inadequacy. Our nation suffered for my mistakes. I see now that I was unfit for it all from the start."
S: "That's not true! You can't let your past determine the future! Equestria is stronger united than apart, surely you must realize this! That's why we have to unite the crystals and bring magic back! Please, Princess Luster Dawn, help us make things right!"
L: "I once thought as you did, Sunny. But believe me, you and your friends are better off without a disappointment like me. I wish you good fortune on your journey, and maybe you'll be able to do what I never could."