Electricity

Electricity is a form of energy. In its most harmless form, electricity is what many species across the universe used as power.

Electricity can also be harnessed as a weapon. Racnoss webstars could discharge electrical blasts from any of its pointed spires. (DW: The Runaway Bride)

Davros could fire electrical charges from his cybernetic arm gauntlet which ranged from minor to fatal voltage. (DW: Journey's End)

The Cybermen could electrocute victims through their arm gauntlets, killing them instantly. (DW: Rise of the Cybermen)

Bannakaffalatta, being a cyborg, had the ability to emit a high-range electromagnetic pulse. This destroyed the Heavenly Host easily, but without immediately available medical facilities, it cost him his life. (DW: Voyage of the Damned)

The Slitheen harnessed electricity as a weapon during their first Earth invasion and attached electrical transmitters to name tags using them to zap half of UNIT's alien experts. (DW: Aliens of London)

The newly resurrected Master was able to shoot bolts of electricity from his hands. (DW: The End of Time))

Dæmons (DW: The Dæmons) and the Rutan Host (DW: Horror of Fang Rock) also used electricity as a weapon.

Some species like the Wire could physically transform themselves into electricity and travel across galaxies in that form. (DW: The Idiot's Lantern)

The Swarm infected its hosts through electrical pathways. (DW: The Invisible Enemy)

Daleks used electric barriers to protect themselves from Terrorkons while storing missiles in the Lake of Mutations. (TV21: The Terrorkon Harvest)