Unbounded Potential

Two modes that pull apart on the board, and an entwine cost that lets you take both. Placing +1/+1 counters on up to two creatures wants targets to seed; proliferate wants a battlefield already thick with counters (loyalty, charge, +1/+1, poison, anything else lying around). Split them and you often have one useful mode and one dead one. Pay the entwine tax and you seed the counters first, then multiply them, resolving the whole chain in a single instant. That converts a modest pump into an actual swing, and the instant-speed window means the mana can sit open during an opponent's turn while you decide which half matters: a combat trick, a poison closer, a loyalty top-off. Earlier proliferate payoffs mostly demanded a home up front, a +1/+1 shell or a counter-heavy superfriends build, and cast at sorcery speed. Stapling counter-placement to proliferation, and letting one instant buy both, serves either audience without settling the deck's identity before the game starts. The entwine cost is why the cheap single-mode line does not simply outclass the older sorcery-speed spells: the flexibility is bought with real mana rather than handed over for free.