Accepting new power, not a single craftsman is unbiased (3-8)
I believe the answer is:
non-partisan
'unbiased' is the definition.
(I've seen this before)
'accepting new power not a single craftsman' is the wordplay.
'accepting' is an insertion indicator (inserted letters are accepted).
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'power' becomes 'p' (symbol in physics).
'not a single' becomes 'no' (in a phrase like 'no man is an island').
'craftsman' becomes 'artisan' (synonyms).
'n'+'p'='np'
'no'+'artisan'='noartisan'
'np' inserted into 'noartisan' is 'NON-PARTISAN'.
'is' acts as a link.
(Other definitions for non-partisan that I've seen before include "Taking neither side" , "Impartial" , "Objective" , "Free from affiliation or bias" , "Favouring neither side" .)