Because... Hiling's brother made her to be a spy and had her put in Celestial Being only she didn't know it. Because she was my twin, I could track them through her. I was the one who gave her back her memories and took control of her briefly.
[He pauses for a moment, an almost defeated look on his face. He wasn't proud of that. That was when he started to release maybe there was something wrong with what they were doing]
Hiling and her brother made Anew fight Celestial Being. I said it was in bad taste... since she had fallen in love with one of them. Ribbons took control of her so she tried to kill the one she loved and one of his teammates killed her to save him.
[He's looking down now, because he doesn't really want to look at her. He hated those moments of his life now and it just seemed to remind of everything he had done that he might have been able to change]