Killer of hunted animal guarding southern city once (9)
I believe the answer is:
destroyer
'killer' is the definition.
(I've seen this before)
'hunted animal guarding southern city once' is the wordplay.
I cannot really see how this works, but
'southern' could be 's' (abbreviation) and 's' is located in the answer.
'city' could be 'troy' (Troy is an example) and 'troy' is present in the answer.
'animal' could be 'deer' (I've seen this before) and 'deer' is present in the remaining letters.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
'of' is the link.
Can you help me to learn more?
(Other definitions for destroyer that I've seen before include "likely to break down" , "Saboteur" , "Apollyon's" , "Wrecker" , "Vandal" .)