Fitzroy (The Devil and Miss Carew)

"Fitzroy" was a mysterious entity, named after one of the regions in the Shipping Forecast.

Powers and Abilities
Fitzroy lived in space, but was capable of communicating with those on Earth using radio broadcasts. It could insinuate itself in the programs, talking in the voices of the broadcasters. It could also grant or take away life, revitalise the old or kill them.

Fitzroy was repelled by electricity, specifically the kind caused by technology. This prevented it from coming to Earth. (BBCR: The Devil and Miss Carew)

History
Fitzroy lived alone in space for an unknown period of time until it wanted a place to live. It came to Earth, but was repelled by the electricity in human technology. It planned to disable all technology on Earth, allowing it to live there. It contacted several elderly people who had previously had the resources to do such things. It offered them more life in exchange for their help. Some, like Bryn Williams, refused and were killed. Others, like Joanna Carew, were sent back to work on means to shut down the electricity.

Torchwood Three eventually detected the energy fluctuations that Fitzroy was causing. Jack Harkness and Ianto Jones tried to follow it. In the meantime, Gwen Cooper found out about Miss Carew's remarkable recovery and tried to investigate that, in turn learning of Miss Carew's virus to shut down all the power stations. When Gwen tried to confront her, she was able to overpower Gwen and lock her up just before the plan was complete. The only snag was the satellite dish to broadcast the virus, which Miss Carew had to adjust manually. Rhys Williams was able to free Gwen and when she confronted Miss Carew, Miss Carew lost her grip and fell. With that the virus couldn't be transmitted and Fitzroy's plan failed. (BBCR: The Devil and Miss Carew)