Risk everything in attack, shattered (2,3,5)
I believe the answer is:
go for broke
'risk everything' is the definition.
(I've seen this in another clue)
'attack shattered' is the wordplay.
'attack' becomes 'go for' (go for can mean to attack).
'shattered' becomes 'broke' (I've seen this before).
'gofor'+'broke'='GO FOR BROKE'
'in' acts as a link.
(Other definitions for go for broke that I've seen before include "Make all-or-nothing effort" , "Gamble everything" , "Risk everything in an all-out effort" , "Make an all-out effort" .)