One who starts things - often provocatively (10)
I believe the answer is:
instigator
(Other definitions for instigator that I've seen before include "One setting off" , "prime mover" , "starter" , "One who initiates (something)" , "Stirrer" .)
I believe the answer is:
instigator
(Other definitions for instigator that I've seen before include "One setting off" , "prime mover" , "starter" , "One who initiates (something)" , "Stirrer" .)