Guardian's gripping article is utterly bizarre (8)
I believe the answer is:
tutelary
'guardian's' is the definition.
(synonyms)
'gripping article is utterly bizarre' is the wordplay.
I cannot quite see how this works, but
'article' could be 'a' (the indefinite article in English) and 'a' is found within the answer.
an anagram of 'utterly' is 'tutelry' which is located in the remaining letters.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for tutelary that I've seen before include "Like the Guardian" , "Serving as guardian, giving protection" .)