Energy blaster

Energy blasters were used by the Preachers on Pete's World to kill the Cybermen. They killed by firing a blue blast of concentrated energy.

History
The Tenth Doctor modified some blasters to penetrate the heat shields and polycarbide of a Dalek; enough to create a battle long enough for Rose and Mickey to escape, but not to the point where the Daleks would be destroyed. The blasters disabled the Cult of Skaro's weapons and impaired their casings, though they quickly adapted and regained control of their weapons. (TV: Doomsday)

Upgraded versions of these guns were developed by the parallel world's Torchwood and used by Rose Tyler, Jackie Tyler and Mickey Smith. They fired a narrower, more opaque beam which could easily destroy a Dalek. (TV: The Stolen Earth / Journey's End)

The weapons room of Torchwood Three contained blasters, but the room was locked when Lisa Hallett attacked so they could not use them. (TV: Cyberwoman)

By the time the Cybermen joined the Alliance, they had incorporated similar weapons into their arsenal. The Cybermen accompanying the Cyber-Leader when the Eleventh Doctor was imprisoned under Stonehenge carried the weapon. Two were also hidden in the chamber, used by the Cyberman guarding the Pandorica before a group of Romans found and fought against it, leaving it only one arm that still used the blaster on its wrist, meaning it was unable to fire the weapon. (TV: The Pandorica Opens)

The weapon was still in use when the Cybermen organised into the Cyber Legions, (TV: A Good Man Goes to War, GAME: The Eternity Clock) although they continued to use wrist blasters as well. (GAME: Blood of the Cybermen, PROSE: Plague of the Cybermen)