Incite Hysteria

Strip blocking from an entire color of the defending board, and you have turned the classic Falter effect (one creature can't block, clear a lane for lethal) into something that scales to a whole defending line for one card. The reach comes from how the keyword resolves: you target a single creature, then the effect ripples to every other creature sharing any of its colors. Against a mono-colored wall it shuts the door on the entire board; against a multicolor opponent the targeting becomes a small puzzle, since you pick the creature whose color overlap catches the most relevant blockers, sometimes sweeping wider than the obvious threat and sometimes narrower. That conditionality is the price the keyword charges for hitting many bodies on one spell. The breadth runs through your own creatures too in the matching colors, but "can't block" rarely stings the player who is already swinging out. What you are paying for is the turn you intend to end the game: a wide, fast board and a defending wall that suddenly cannot interpose. As an attack-enabler it does not kill anything, which is both its limitation (the blockers survive to wall up next turn if your alpha strike stalls) and its appeal (it dodges destruction-based answers entirely and asks only that you have the bodies to capitalize).