Whatever may happen during whatever trial (2,3,4)
I believe the answer is:
in any case
'whatever may happen' is the definition.
I can't judge whether this definition defines the answer.
'during whatever trial' is the wordplay.
'during' becomes 'in' (e.g. during February means in February).
'whatever' becomes 'any' (anything whatsoever).
'trial' becomes 'case' (I've seen this in other clues).
'in'+'any'+'case'='IN ANY CASE'
Can you help me to learn more?
(Other definitions for in any case that I've seen before include "Besides" , "Lawyers may be so employed" , "At all events" , "No matter what" , "Where a customs officer may search" .)