All Nightmares get +1/+1.
, 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 leaves the battlefield, exile all Nightmares.

At the beginning of your upkeep, sacrifice this creature unless you put two cards from your graveyard on the bottom of your library.
, Discard a card: You may have this creature assign its combat damage this turn as though it weren't blocked.

At the beginning of your upkeep, you lose 1 life.
At the beginning of your upkeep, you may return target creature card from your graveyard to the battlefield. That creature gains haste until end of turn. Exile it at the beginning of the next end step.

When this creature enters, target player loses 6 life.
When this creature leaves the battlefield, that player gains 6 life.
: Regenerate this creature.

You don't lose the game for having 0 or less life.
When you have 20 or more life, you lose the game.
Whenever you lose life, you gain 2 life for each 1 life you lost. (Damage dealt to you causes you to lose life.)

Flying, first strike

When this creature enters, exile two target lands.
When this creature leaves the battlefield, return the exiled cards to the battlefield under their owners' control.
: This creature gets +1/+0 until end of turn.

Flying
When this creature enters, if you cast it from your hand, exile all cards from target opponent's hand.
When this creature leaves the battlefield, return the exiled cards to their owner's hand.