Specifically make them feel like they mentally went through what ever traumatic thing happened to an anime character of your choosing. This has a 50/50 chance of either making them commit suicide or completely breaking their mind and giving them some of disorder.

Edit: You can control exactly how much the trauma affects them so forget everything above this. You can put them through all the pain a main character has been through like Naruto but they don’t experience the development and everything that happened to a character like Naruto for them to be able to heal and deal with there trauma. Make them scared to go outside afraid to watch anime. You can decide how much the trauma effects them