In various ways, to attack (3,2)
I believe the answer is:
set on
'attack' is the definition.
('set on' can be a synonym of 'attack')
'in various ways to' is the wordplay.
'in' indicates putting letters inside.
'various ways' becomes 'sen' (compass directions).
'sen' enclosing 'to' is 'SET ON'.
(Other definitions for set on that I've seen before include "Attack" , "Determined" , "Go" .)