The demon king gifted you, a magical life size doll to his three sons, in the middle of a holy war because your existence can enhance their power so long and you’re around them. You were human once but then you died and now you’re here and Meliodas’s as well as his younger brothers personal property, you’re a mix between a servant, toy, pet, and forced companion. There are consequences if you try and leave, this takes place in the Seven Deadly Sins universe