Real phantom has character (5)
I believe the answer is:
alpha
'character' is the definition.
(I know that alpha is a type of alphabetic character)
'real phantom has' is the wordplay.
'has' indicates the answer is hidden within the clue.
'ALPHA' can be found hidden inside 'real phantom'.
(Other definitions for alpha that I've seen before include "Top star" , "Most prominent star" , "First letter of the Greek alphabet" , "high mark" , "best score" .)