Underworld Breach

Oracle Text
Each nonland card in your graveyard has escape. The escape cost is equal to the card's mana cost plus exile three other cards from your graveyard.
At the beginning of the end step, sacrifice Underworld Breach.
Each nonland card in your graveyard has escape. The escape cost is equal to the card's mana cost plus exile three other cards from your graveyard.
At the beginning of the end step, sacrifice Underworld Breach.
Instant staple in EDH with tons of possible combos and possible applications in non-rotating formats.