Skilful editor supporting story, not disheartened (8)
I believe the answer is:
talented
'skilful' is the definition.
(having a talent or skill)
'editor supporting story not disheartened' is the wordplay.
'editor' becomes 'ed' (abbreviation).
'supporting' is a charade indicator (letters next to each other) (in a down clue, some letters go below others).
'story' becomes 'tale' (synonyms).
'disheartened' means to remove the middle letters (the middle or heart is removed).
'not' with its middle removed is 'nt'.
'tale'+'nt'='talent'
'ed' after 'talent' is 'TALENTED'.
(Other definitions for talented that I've seen before include "Having natural or special ability" , "Naturally gifted" , "Having a natural aptitude or skill" , "Showing a natural aptitude" , "Endowed with gifts" .)