King at heart is impartial and really quite cold resulting in an unfair outcome (9)
I believe the answer is:
injustice
'king at heart is impartial and really quite cold resulting' is the definition.
I can't tell whether this defines the answer.
'in an unfair outcome' is the wordplay.
'an unfair outcome' becomes 'justice' (I have seen 'right outcome' mean 'justice' so perhaps 'outcome' could also mean 'justice'. I am not sure about the 'unfair' bit.).
'in'+'justice'='INJUSTICE'
Can you help me to learn more?
(Other definitions for injustice that I've seen before include "It's unfair" , "Lack of fairness" , "Unfairness" , "wrong" .)