Chainer, Lord of the Perverse

Non-nightmare creatures get -1/-1.
{1}{w}{b}, Pay 3 life: Put target creature card from
a graveyard onto the battlefield under your
control. That creature is black, white, and is a
Nightmare in addition to its other creature types.
When Chainer, Lord of the Perverse leaves
the battlefield, exile all creatures put onto
the battlefield with it.