Herigast, Erupting Nullkite

Emerge was built to bridge cheap creatures into expensive Eldrazi, converting a body on the battlefield into a discount on the mana cost. This turns that mechanic into an engine rather than a one-time ramp trick: while it is out, every creature spell you cast gains emerge, with the cost pinned to that creature's own mana cost. The practical effect is a self-feeding chain where each creature sacrificed to cast the next reduces what the next one costs, so a board of small bodies can spiral into progressively larger threats without ever paying full price. Exiling your hand to draw three keeps that chain supplied, refilling the fuel exactly when a big emerge cast has emptied it. What holds the design together is that the emerge cost it grants equals mana cost, not mana value, so it stays keyed to the printed number rather than a card's adjusted value. Even reaching the point where any of this matters demands committing a 6/6 flier to the board, whether hardcast for its full nine or emerged in by sacrificing a creature to shave the reduced red-heavy cost. It is a payoff that rewrites how a whole creature deck sequences, but only after you have paid to turn the engine on.