Electrical devices of a wicked slayer (6)
I believe the answer is:
relays
'electrical devices' is the definition.
(I've seen this in another clue)
'a wicked slayer' is the wordplay.
'a wicked' indicates an anagram.
'slayer' anagrammed gives 'RELAYS'.
'of' is the link.
(Other definitions for relays that I've seen before include "Passes on in multi-runner races" , "Passes on a message" , "Rebroadcasts" , "Races with team members who pass a baton" , "Races for teams of four" .)