Blue? It's bad for beastly bloke ..... (6)
I believe the answer is:
sadist
'beastly bloke' is the definition.
The definition and answer can be both people as well as being singular nouns.
Perhaps you can see an association between them that I can't see?
'blue? it's bad' is the wordplay.
'blue?' becomes 'sad' (similar in meaning).
'bad' is an anagram indicator.
'its' is an anagram of 'ist'.
'sad'+'ist'='SADIST'
'for' acts as a link.
Can you help me to learn more?
(Other definitions for sadist that I've seen before include "An amalgam, made up of two or more parts" , "Person who likes to inflict pain" , "Cruel person, takes pleasure in it" , "Cruel type" , "One who enjoys inflicting pain on others" .)