It's revealed after strike - it's the final blow
I believe the answer is:
knockout
'the final blow' is the definition.
'it's revealed after strike' is the wordplay.
'it's revealed' becomes 'out' (I've seen this in other clues).
'after' means one lot of letters go next to another.
'strike' becomes 'knock' (knocking is a kind of striking**).
'out' put after 'knock' is 'KNOCKOUT'.
'it's' is the link.
(Other definitions for knockout that I've seen before include "Incredibly OK" , "reverse of OK?" , "Final stroke" , "Act of rendering unconscious" , "Stunning blow" .)