"Paradise Lost” schemer (5)
I believe the answer is:
satan
'paradise lost schemer' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for satan that I've seen before include "arch-fiend" , "The devil, Beelzebub" , "Diabolical figure" , "Fiend" , "Apollyon" .)