It's not the worst when monster is skewered by final speaker - a loyal associate (4,6)
I believe the answer is:
best friend
'associate' is the definition.
(I know that best friend is a type of friend)
'it's not the worst when monster is skewered by final speaker a loyal' is the wordplay.
I cannot quite understand how this works, but
'it's' could be 'es' ('e' can mean 'electronic' which is similar to 'IT') and 'es' is located in the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is located in the answer.
'final' could be 'end' (synonyms) and 'end' is present in the answer.
'speaker' could be 'i' ('I' refers to the person saying it) and 'i' is located in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for best friend that I've seen before include "Mate" , "Bosom companion" .)