Devolver

The Devolver was an invention created by the Wraxians using technology left by the Kotturuh.

The Wraxians used the Devolver to eliminate enemy's by reverting them through generations of ancestry until the Wraxians were exterminated by the Dalek Time Squad. (AUDIO: The Enemy of My Enemy)

At a later point acquired the Devolver and miniaturized it into a more portable version and used it to steal a map from the Repository, killing many in his way with the Devolver. (AUDIO: Master Thief)