Culling Mark

Lure works by flooding a creature with mandatory blocks; this strips a single creature of its choice not to block at all. The distinction is the whole effect. Compel one defender into the combat math and you have either opened a hole for the rest of your attackers to walk through or pointed an attacker into a creature you intend to kill, taking away the option to hold back, chump elsewhere, or sit the turn out. The catch is the "if able" clause doing exactly what it says: whether the creature must block is checked when blockers are declared, so a target that cannot legally block then (tapped, or with no attacker it can legally be assigned to) is untouched by the compulsion, and when you cast matters as much as what you target. This is a green answer to a defensive wall that costs no removal, a way to turn a board stall into a forced trade, the fight-adjacent trick green reaches for when it cannot just go over the top. The sorcery speed is the tax: you commit during your own main phase, before combat, telegraphing the play and handing the opponent a priority window to respond, sacrifice the target, or pump it before blocks lock in. That narrow window is what keeps a one-creature removal-by-combat effect from being a clean two-for-one, and it means the card lives or dies on whether your other attackers can capitalize the instant the block is forced.