Emerge

Emerge is a keyword ability introduced in Eldritch Moon that provides an alternative cost for a spell when sacrificing a creature. Emerge was designed by Sam Stoddard's development team, and inspired by the old ninjutsu mechanic.

In Eldritch Moon, each Emerge cost was 1 mana lower than the converted mana cost, but included at least one colored mana. Emerge was associated with Green, Black, and Blue. It was only present on expensive colorless Eldrazi creatures, all but one of which contained a "When you cast this..." ability.

While various creatures in Eldritch Moon are designed to be enablers for Emerge, Foul Emissary is the only card to specifically reward Emerge mechanically.