Brilliant story, 'Knight Time' -- needs editor (8)
I believe the answer is:
talented
'brilliant' is the definition.
(I've seen this before)
'story knight time needs editor' is the wordplay.
'story' becomes 'tale' ('tale' can be a synonym of 'story').
'knight' becomes 'n' (chess).
'time' becomes 't'.
'needs' is a charade indicator (letters next to each other).
'editor' becomes 'ed'.
'tale'+'n'+'t'+'ed'='TALENTED'
(Other definitions for talented that I've seen before include "Skilled" , "Possessing aptitude" , "Possessing ability" , "Naturally gifted" , "Having special or great ability" .)