Warning from victim pierced by arrow perhaps (10)
I believe the answer is:
precursory
'warning' is the definition.
(thesaurus)
'victim pierced by arrow perhaps' is the wordplay.
'victim' becomes 'prey' (prey is a kind of victim).
'pierced by' means one lot of letters goes inside another (some letters pierce a hole in others).
'arrow perhaps' becomes 'cursor' (I am not sure about this - if you are sure you should believe this answer much more).
'prey' enclosing 'cursor' is 'PRECURSORY'.
'from' is the link.
Can you help me to learn more?
(Another definition for precursory that I've seen is " Serving to introduce".)