Before demise, finally try to make different close friend (5,3)
I believe the answer is:
'close friend' is the definition.
'before demise finally try to make different' is the wordplay.
'before' is a charade indicator (letters next to each other).
'finally' indicates one should take the final letters.
'try' becomes 'go' (go is a kind of try).
'to make different' becomes 'alter' (I've seen this before).
The last letter of 'demise' is 'e'.
'ego' put after 'alter' is 'ALTER EGO'.
(Other definitions for alter ego that I've seen before include "Other half" , "Go, relate to other self" , "Hidden self or very close friend" , "One's secondary personality" , "Similar character" .)