Tooth and Nail

The two modes are almost beside the point: the whole card was built to be entwined. Pay the extra two mana and you tutor for any two creatures and slam them straight onto the battlefield in one sorcery, which collapses the spell into a one-card combo engine that only asks you to name the right pair. The entwine cost is the design constraint doing the load-bearing work: at seven mana you get modal flexibility, but the kill is gated behind nine total, the kind of number a dedicated green ramp deck was being engineered to reach a turn or two ahead of schedule. Find two creatures whose presence together ends the game and you have skipped every step between "I have lands" and "I win." The artifact-creature density of its original environment made that pairing trivial to assemble, and the card defined an entire ramp archetype named after itself, a deck whose only plan was to hit the entwine number and resolve this. The cleverness of the design is that it externalizes its own power level: the spell is exactly as broken as the best two creatures you can put onto the battlefield with it, so its danger scales with every set printed afterward. The text never changed; the pool of creatures around it kept getting better, which is why a card from green's early big-mana era keeps finding new ceilings to break.