Wields, as influence (6)
I believe the answer is:
exerts
'wields as influence' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for exerts that I've seen before include "Brings something to bear forcefully" , "Brings into use or to bear" , "Makes strenuous effort" , "Brings into use, say strength" , "Makes use of" .)