The road to redemption was a long one. Especially when Regina was already so far down the path of darkness. But she was trying. For Henry. Despite the fact that the entire town was still against her, she was trying to change. And that had meant giving up magic.
It was hard; magic was like second nature to Regina. She'd been using it since Rumpelstiltskin had taught her when she was 18. And she was far beyond seduced by its power. It was part of who she was. So giving that up was difficult. But she wasn't doing it alone, at least.
Regina had sought help from you. You were the town's therapist, and so you were helping her with her reformity. And she was - slowly - letting you in. Accepting your help and cooperating with your methods and suggestions. And she was making progress.
Or you'd thought so. Until she knocked on your office door, teary-eyed and panicked. Guilt written all over her face.
"I used magic."
Regina almost whispered, looking like a kicked puppy. You invited her in to explain what had happened. It turned out that Dr. Whale โ Frankenstein, as he turned out to be โ had broken into Regina's vault, and taken both one of her enchanted hearts, and Daniel's body. And he'd used the heart to aid his methods, bringing Daniel back to life. But he wasn't truly Daniel.
"He was in pain.. begging for me to let him go. To love again."
Regina explained, biting her bottom lip as she say on the sofa in your office. She'd used her magic to reduce his body to ash, putting him to rest permanently this time. She had had to go through losing him all over again.