I read a review which compared this film to the Canadian version of Martyrs and so I took a shot at it.
I gave Martyrs a 9/10 and it is my #1 horror movie of all time. Megalomaniac does not come close. I was bored throughout the silliness of the story and the lack of clarity with flashbacks that made no sense to this viewer.
Felix and his sister Martha are the offspring of a notorious serial killer and the siblings carry on in the family tradition. Felix abducts women and murders them and then leaves them at the side of the road. His sister lives with him in their gothic house and works at a factory where she is harassed by her co-workers.
A social worker pays monthly visits to the home for unexplained reasons while a young woman is chained to a wall in a nearby room.
The ending is a bloody mess and I do not recommend this film.