Eternal Night

Eternal Night enters the battlefield tapped.
Ignore all Light-Triggers until Eternal Night leaves the battlefield.
Light: {t}: Switch to Dark.
Dark: {b}{b}{t} : Search your library for a Swamp and exile it face down, then shuffle your library. When Eternal Night leaves the battlefield return all face down exiled swamps to your hand.
Pay 2 Life: Sacrifice Eternal Night.