Such Lovely Skin - Tatiana Schlote-Bonne

Viv isn't known for telling the truth, but she's not lying about having an evil doppelganger.

After spending the summer wracked with guilt about causing the accident that killed her little sister, ambitious gamer and chronic liar Viv returns to Twitch streaming. She never told her parents the truth about the accident, but she hopes that maybe making it big in streaming and giving the money to them is penance enough for her mistakes.

The weekend before school starts, Viv finds the perfect horror game to make her Twitch comeback, and during an offline practice run, an NPC asks Viv for a secret. She decides to tell them the truth about her sister's death since a game could never share her secret-in doing so, she accidentally welcomes a demonic mimic into her life.

No one believes Viv when she tells them about her evil doppelganger. Viv has lied to get her best friend's sympathy and has spread rumors for attention, so why should anyone trust her now? The only person who believes her is Ash, a cute social outcast whom Viv once bullied. In trying to clear her name and kill the mimic, Viv discovers that her lies have hurt people who never deserved it, herself included.