Inspired by the true story of the “Butcher of Mons” who murdered five women between 1996 and 1997 (and was never caught), the new Belgian thriller “Megalomaniac” is an artful and unrelenting look at madness and murder through the eyes of a psychopath. What sets this film apart from the tonnage of serial killer films in existence, is the fact that writer/director Karim Ouelhaj examines the “sins of the father” rather than going for another procedural.