Observe the fashion in any Shakespearean character (4,6)
I believe the answer is:
mark antony
'any shakespearean character' is the definition.
The definition suggests a singular noun which matches the answer.
'observe the fashion' is the wordplay.
'observe' becomes 'mark' (marking is a kind of observing).
'the fashion' becomes 'antony' (I can't explain this - if you can you should believe this answer much more).
'mark'+'antony'='MARK ANTONY'
'in' is the link.
Can you help me to learn more?
(Other definitions for mark antony that I've seen before include "general" , "classical role" , "Roman politician and lover of Cleopatra" , "borrower of ears" .)