Only two revolutionaries brutally killed (9)
I believe the answer is:
butchered
'brutally killed' is the definition.
'only two revolutionaries' is the wordplay.
'two revolutionaries' can mean two substitutions for 'revolutionary'.
'only' becomes 'but' (I've seen this before).
'revolutionary' becomes 'che' (Che Guevara the Marxist revolutionary).
'revolutionary' becomes 'red'.
'but'+'che'+'red'='BUTCHERED'
(Other definitions for butchered that I've seen before include "Massacred" , "may be killed" , "slaughtered" , "Killed brutally" .)