Frost tells Kimura that she is nothing but a bully who harms others like Laura despite knowing how painful it is to make up for her own abusive childhood. Frost then mind-wipes her, making her forget about her grandmother—the only influential and positive person in her life—creating "a deep void that will cause [her] pain for a lifetime."
Frost reveals to Kimura that she's just a bully like Laura, despite being aware of the pain it causes. Frost then erases her memories, causing Kimura to forget about her grandmother, the one person who had a positive impact on her life, leaving her with a profound emotional void.