Among the Tech-Priests of the the Cult Mechanicus stand the Electro-Priests, a holy sect of warriors that dedicate their lives to the Motive Force, the life energy that powers everything in the universe. Upon induction into their holy order their bodies are threaded with electoos that allow them to conduct vast amounts of electricity. Some use this power to steal the life energy of their foes, while others use it to electrocute them in the most shocking fashion.
Corpuscarii Electro-Priests believe the Motive Force should be used to obliterate the enemies of the Machine God at every opportunity. To them, no amount of force is too great and they use their bodies as living conduits for the Machine God’s wrath, scything down their foes with arcs of coruscating lightning.
Fulgurite Electro-Priests have a very different take on the Motive Force. They believe it should be stored and denied to unbelievers, that only the worthy should be allowed to use it and, even then, only frugally.
When the Fulgurites march to war they use electroleech staves to wrench bio-electric energy from their targets, thereby sapping the unworthy of the Motive Force.
You can find out more about the Electro-Priests in White Dwarf 69, which includes a stage-by-stage painting guide and rules for using them in your battles.