This is just a collection of ideas that might work with the dark/ multiple personality idea.
- Broken mirror symbolising that the dark half has taken control
- Code/ message written in blood
- Shadow - something creaping into space, symbolising the darkness within
- Marks that belong to insane patient, prisoner, etc - finger nail scracthes, destroyed objects, smeared blood, ripped curtains, etc
- Setting - could take inspiration of the play room in the Haunted, an abandoned room once a space of happiness but became cold and uncanny or could literally be a disturbing space such as a prison or dugeoun cell
- Aftermath - coming into the room after events have taken place.