Birthing Pod

The descendant of Survival of the Fittest, rebuilt around a +1 stepladder instead of free discard-and-tutor. The change of axis is the whole design: where its ancestor turned any creature in hand into any creature in the library at instant speed, this one converts a creature already on the battlefield into one exactly one mana value higher, dropping it directly onto the field rather than into your hand. That single-step constraint is what makes it a curve to climb rather than an open search engine: you assemble a chain (a one-drop fetches a two-drop fetches a three-drop), and each link must already be sitting in the library at the right rung. The sorcery-speed clause keeps it from popping off on the opponent's turn, and the sacrifice cost means every activation feeds death triggers and persist loops, which is exactly where the card became dangerous enough to draw a Modern ban for the deck built entirely around recurring small creatures into a value spiral. The Phyrexian mana in both the cost and the activation gives the engine its grind: under pressure you can deploy and keep cranking it while paying life instead of green, a real out when the chain is the only thing keeping you alive. A tutor that builds in increments, rewarding a deckbuilder who lays out a coherent ladder of creatures rather than a pile of unconnected bombs.