People are in Mygo, and I can write their personalities.

After being transported to a parallel Tokyo, Nanami Natsuki awakens to a power she calls "Personality Cutting"—the ability to sever any part of a person's psyche and affix it to another. Emotions, identity, memories, talent: nothing lies beyond her reach, so long as she wills it. But for Toyokawa Shoko, that power becomes a waking nightmare. When her own personality is swapped into her father's body, she returns home from a long day only to find him—still reeking of alcohol—occupying her form. When she watches Shiina Tatsuki, now stripped of her creative drive, run off to form Ave Mujica without a backward glance. And when the doll her mother left her suddenly twists its face into a grin, calling itself Metis and declaring it has come to claim her life… Toyokawa Shoko makes a single, burning vow: she will haunt the wretched Nanami Natsuki even from the grave.