Nico had never tried to heal someone while they were in the process of being eaten alive before. So that was a new, horrifying experience that she'd like to never ever have to repeat again. Then, when Bunny jumped to his feet and told her to keep doing what she was doing and then jumped into the fire, well, she couldn't very well stop doing it.

She did fall to her knees though, the smell of burning flesh tickling the back of her throat in a way that promised to end poorly, her mind flashing to a boy's skeleton burnt free of flesh and muscle and blood in a bare moment not three feet from where she'd stood...

The Staff kept burning with violet flame even after Bunny had pulled out of the fireplace and kicked the tick back into it alone. She wasn't thinking, about stopping the spell or keeping it going, she just sat there still and stunned and silent, waiting for some kind of jolt to knock her back into reality again.