Chainer, Dementia Master

All Nightmares get +1/+1
{b}{b}{b} Pay 3 life: Put target creature card from a graveyard into play under your control. That creature is black and is a Nightmare in addition to its creature types.
When Chainer, Demetia Master leaves play, remove all Nightmares from the game

You're never getting out of this place,
welcome to Suffocate City.