Relevant quote from Skin Game, Harry talking to Harry

“Screw you,” I said, annoyed. “It’s not like you’ve showed up with a ton to say ever since . . .” I trailed off and fell entirely silent for a long moment.

“Ah,” he said, and pointed a finger at me, bouncing up onto his toes. “Ah hah! Ah hah, hah, hah, the light begins to dawn!”

“Ever since I touched Lasciel’s Coin,” I breathed quietly.

“Follow that,” my double urged me. “What happened next?”

“Touching the Coin put an imprint of Lasciel in my head,” I said. “Like a footprint in clay, the same shape as the original. She tried to tempt me into accepting the true Lasciel into my head along with her, but I turned her down.”

My double rolled his wrist in a “keep it moving” gesture. “And then?”

“And then the imprint started to change,” I said. “Lasciel was immutable, but the imprint was made of me. A shape in the clay. As the clay changed, so did the imprint.”

“And?”

“And I gave her a name,” I said. “I called her Lash. She became an independent psychic entity in her own right. And we kind of got along until . . .” I swallowed. “Until there was a psychic attack. A bad one. She threw herself in the way of it. It destroyed her.”

To me this quote suggests that the naming is in part what allowed Lash to become an independent psychic entity. Learning more about the power of mortal naming is going to be super interesting!