Cruel type displays a disturbing piece (6)
I believe the answer is:
sadist
'cruel type' is the definition.
(I've seen this in another clue)
'displays a disturbing piece' is the wordplay.
'piece' indicates the answer is hidden within the clue.
'SADIST' can be found hidden inside 'displays a disturbing'.
(Other definitions for sadist that I've seen before include "One who enjoys inflicting pain on others" , "One takes pleasure in inflicting pain" , "One who enjoys cruelty" , "Tormentor" , "One who enjoys making others suffer" .)