Diabolical cast in a production (7)
I believe the answer is:
satanic
'diabolical' is the definition.
('satanic' can be a synonym of 'diabolical')
'cast in a production' is the wordplay.
'production' is an anagram indicator.
'cast'+'in'+'a'='castina'
'castina' with letters rearranged gives 'SATANIC'.
(Other definitions for satanic that I've seen before include "Diabolical" , "like Mephisto" , "Bad" , "Like the Devil" , "Relating to the devil" .)