Green Sun's Twilight
Green Sun's Zenith fetched exactly one creature straight to the battlefield; this reworks that impulse into a tiered dig, and the tier is where the design lives. Pay a small X and it is a selection spell, revealing X plus one cards off the top and pulling a creature and/or a land into hand while the chaff scatters to the bottom in random order. There is no guarantee both types appear in that reveal: at low X you are more often taking whichever one shows up, and only when the pile is deep enough do you reliably line up a body alongside a land. Push X to five (a full six mana with the green pip) and the spell rewrites itself: the chosen cards can arrive directly on the battlefield instead of your hand. That six-mana threshold is the entire balancing act. Below it, you trade card quantity for filtering toward what you need; at it or above, you have paid full retail to cheat a creature into play and land a free permanent beside it, but only after committing enough mana that a cheaper play was unlikely anyway. The reveal-and-bottom structure keeps it honest against library manipulation: you see more than you keep, and what you leave scatters where you cannot restack it. The result is one point of X acting less as a scaling dial than as a switch between "dig for what I need" and "put my payoff into play."
