This may be the final version of Mem, but I might continue to tweak a few things here and there depending on how much my skills evolve over time. Anyway, this is The One Who Remembers. She is a lost soul who managed to haunt a game of Undertale. She died from a car crash, and had been so afraid to sleep that she came back as a lost soul. Eh, I'll stop stalling and just post the backstory. Remember, though, I wrote this in one night around 2:00am.
Mem had a relatively boring life at home. Normal parents, normal apartment building, normal school, normal neighborhoods... The only problem she had was her memory. She remembered everything due to a condition called Hyperthymesia. This lead to Mem being dissatisfied with many things in her school and the people attending it. Her parents were extremely understanding of it and moved away to a more lively city, where she could gain new and exciting memories rather than live out the same thing every day. At first, Mem enjoyed the new scenery, but she began to witness crime more often, and it bothered her slightly. This was when Hyperthymesia began to haunt her, replaying those scenes of violence in place of dreams. It even went to the point where Mem began to drink coffee to keep her up at night, despite her performance the next day suffering greatly.
As time went on, Mem's parents took her to see a psychiatrist in hopes of solving the issue. All had been going relatively well, still a lot of bumps and potholes, but smooth riding nonetheless. Weeks passed and Mem had witnessed a mass murder, traumatizing her for what would be her last few days. It was the third day since Mem had witnessed the murder and her parents were driving her home from the psychiatrist. The traffic lights had been turned off for god knows why and a pick-up had hit Mem's father's car on the driver's side, killing her and her father. Unfortunately for Death, Mem was so terrified of sleeping that she willed her soul to be bound to the earth, never to fall asleep for eternity.
Mem now wanders the earth as a lost soul. Passive, but still very creepy due to the injuries she sustained during the crash. Bandages and a turtleneck cover the reason for her lack of speech, while her hoodie pocket hides the injuries of her hands. Her phantom hands, however, show the injuries due to them being linked to Mem's body in some way. Just recently, Mem managed to haunt a disk with Undertale burned into it, causing her to develop her "magic". She uses sign language to speak, but sometimes practices speaking in hands like Gaster just to be a goofball. Her Hyperthymesia still haunts her, though, and causes violent nightmares whenever she falls asleep. The only thing her Hyperthymesia hasn't gotten a hold of is her name, as she was always called Mem, or Mem'ry; even Memmey by her parents sometimes by children.