To make poor devil take over is hard (10)
I believe the answer is:
impoverish
'to make poor' is the definition.
('impoverish' can be a synonym of 'make poor')
'devil take over is hard' is the wordplay.
'devil' becomes 'imp' (devilish creature).
'take' says to put letters next to each other.
'hard' becomes 'h' (abbreviation used in pencil classifications).
'imp'+'over'+'is'+'h'='IMPOVERISH'
(Other definitions for impoverish that I've seen before include "Make poor" , "beggar" , "Spoil the quality of" .)