As someone who has felt as though he had little to no agency his entire life, Carlisle cannot help but commiserate, even if he cannot fully relate to the situation. To find out she was merely written into existence, her choices predetermined by the whims of a writer -- that is a struggle Carlisle cannot even imagine.

"Those you hurt, then" —he'd thought maybe she was the Hierophant, given what they were talking about and the way she worded it, but he assumes he may be wrong now that she mentions someone else— "who were they? And would they have not also been written into being?"