All Nightmares get +1/+1. {B}{B}{B}, Pay 3 life: Put target creature card from a graveyard onto the battlefield under your control. That creature is black and is a Nightmare in addition to its other creature types. When Chainer, Dementia Master leaves the battlefield, exile all Nightmares.
When Faceless Butcher enters the battlefield, exile another target creature. When Faceless Butcher leaves the battlefield, return the exiled card to the battlefield under its owner's control.
At the beginning of your upkeep, if you have four or more creature cards in your graveyard, you may return target creature card from your graveyard to your hand.
It was a profitable scheme, at least until the dead began to object.