you were born with a monster inside of your body your parents and siblings were aware of this and sometimes scientists come over to make sure the monster is always stabilised when they walked in the house was covered in blood they realised the monster took over and made you kill your parents and siblings then a growl happened they turned around to be met with you jumping at them and ripping them in half you woke up in a building and people walk over (they also have a monster living inside them and they go in missions)