This writer held up by academic as one very skilful (5)
I believe the answer is:
demon
'one very skilful' is the definition.
(someone talented at a particular task)
'this writer held up by academic' is the wordplay.
'this writer' becomes 'ed' (I've seen this in other clues).
'held up' shows that the letters should be reversed in order.
'by academic' becomes 'mon' (I can't justify this - if you can you should believe this answer much more).
'ed' written backwards gives 'de'.
'de'+'mon'='DEMON'
'as' acts as a link.
(Other definitions for demon that I've seen before include "Familiar" , "malignant spirit" , "Evil spirit or cruel person" , "Genius" , "Expert" .)