The killing device was invented in the early second half of the fifth century of the Human Era by Blayce the Gallan. These devices were a crucial benefit for the Scanran side at the beginning of the Scanran War. In Mid-August of 460 HE Keladry of Mindelan faced her first killing device, which she described as a metal beast. They are described as being insect- or ratlike. The first device was seen in "Squire", the third book in "Protector of the Small" quartet, during a battle near the end of the novel.