Russian's certainly left-wing, with wicked alter ego (9)
I believe the answer is:
daredevil
'alter ego' is the definition.
The answer and definition can be both people as well as being singular nouns.
Maybe you can see an association between them that I don't see?
'russian's certainly left-wing with wicked' is the wordplay.
'russian's certainly' becomes 'da' (I can't explain this - if you can you should give a lot more credence to this answer).
'left wing' becomes 'red' (red can informally mean communist).
'with' says to put letters next to each other.
'wicked' becomes 'evil' (similar in meaning).
'da'+'red'+'evil'='DAREDEVIL'
Can you help me to learn more?
(Other definitions for daredevil that I've seen before include "Dread evil, being a reckless person" , "Recklessly bold person" , "Intrepid" , "One who enjoys dangerous activities" , "Reckless showoff" .)