Legendary_Person
After her twin sister had been rescued by her father from her kidnappers; she was asked by her father to use Mental Interference Magic on her sister, who was on the verge of a mental breakdown from her experiences of being experimented on by her kidnappers from Dahan. This allowed all of her sister's terrible memories to be converted to simple information in her mind, but because Miya couldn't differentiate between Maya's memories, all of her memories are converted to information. Since memories and experience is what makes a person and his/her personality; Miya, in a sense, killed her sister.