Skywalker cordial but indifferent (8)
I believe the answer is:
lukewarm
'indifferent' is the definition.
(I've seen this before)
'skywalker cordial' is the wordplay.
'skywalker' becomes 'luke' (I've seen this in another clue).
'cordial' becomes 'warm' (similar in meaning).
'luke'+'warm'='LUKEWARM'
'but' acts as a link.
(Other definitions for lukewarm that I've seen before include "Half-hearted" , "Moist" , "Tepid, or less than enthusiastic" , "Not very keen" , "Unenthusiastic" .)