Someone who's made-up about rare catch (9)
I believe the answer is:
character
'someone' is the definition.
(character is a kind of someone)
'about rare catch' is the wordplay.
'about' is an anagram indicator.
'rare'+'catch'='rarecatch'
'rarecatch' with letters rearranged gives 'CHARACTER'.
'who's made-up' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for character that I've seen before include "eccentric individual" , "Eccentric person" , "case" , "Someone in play" , "Distinctive nature" .)