Elemental Uprising

The "must be blocked this turn if able" clause is the part doing the real work, and it points this trick at a different job than most one-shot animation spells. Turning a land into a 4/4 with haste at instant speed is ordinary green tempo: a surprise attacker, a body that ducks sorcery-speed removal because it wasn't on the board when the opponent had priority, a creature that survives a sweeper by reverting at end of turn. But the forced-block rider converts that vanilla body into a lure. Send the 4/4 in and the defending player is compelled to declare a blocker for it if any legal blocker exists, so the Elemental functions less like an extra attacker and more like a tax on their defensive line, dictating that some creature has to trade or chump. The defender still chooses which creature to throw in front of it, so this is combat coercion, not a targeted assassination: you set the terms, they pick the victim. That's the tension it resolves: a temporary creature that costs you a card is usually a bad deal, so the card earns its slot by shaping combat math rather than padding the board. The land staying a land throughout matters too, since it keeps tapping for mana and shrugs off effects that specify nonland permanents; it is still a creature, though, so it dies to anything that targets or sweeps creatures. It wants a developed board, where forcing a block frees the rest of your attack to ride through untouched.