Carmen's abnormality was Plague Doctor. She converted people into her followers and her followers willingly became monsters for her, but one of them started to doubt after all the mess that they created. And so when reality sheds the appearance you see her for who she is, the WhiteNight trying to manipulate everyone into becoming her intended vision.
>b-but Abel looked like WhiteNight
The entire point is that Abel was wrong in his misguided beliefs. He was metaphorically a Distorted Ayin since he doubled down on the ends justifying the means. Ayin realized he couldn't keep being like that and the only way to truly succeed was in genuinely fixing everything up without cutting corners. The Seeds of Light would cure the disease of the mind but fundamentally the choice in the end would be of the people, not like how Carmen, Abel and WhiteNight intended.