Lucius Petrus Dextrus

Lucius Petrus Dextrus was an augur that lived in Pompeii in 79 CE. He visited the Caecilius family on the day before the eruption of Mount Vesuvius. He had built an energy transmitter inside the heart of Mount Vesuvius and planned to use it to convert everyone on planet Earth into Pyrovillian's. He was discovered by The Doctor. The Doctor and Caecilius' son, Quintus, found out that he had breathed in the dust of Mount Vesuvius which is actually the Pyrovile, which was slowly transforming him into stone. The Doctor broke his arm off and escaped, along with Quintus. Later the High Priestess ordered him to advance the prophecy, and in Mount Vesuvius he presented the energy converter to the Pyrovile and they intended to use it to convert all of Earth into Pyrovile. The Doctor destroyed the converter and Mount Vesuvius erupted, killing the Pyrovile and Lucius inside it, along with the rest of Pompeii. (DW: The Fires of Pompeii)

rumors he will return in series 5