Thoughtweft Gambit

A Falter widened to the whole table, with an untap clause carrying the extra freight that justifies a six-mana toll on a one-shot effect. The first half taps every creature your opponents control, and because a tapped creature cannot be declared as a blocker, the clean line is offensive: cast it before you swing and the opposing board loses its defenders for the turn. The untap clause is the second job, and it asks for a specific window. To get both halves working at once, cast it during your own declare-attackers step, after attackers are committed: the same instant the opposing board taps down, your attacking creatures stand back up, ready to block on the crackback. (Declaring attackers is a turn-based action, not a stack object, so the timing is about phases, not responses.) Used purely defensively, the window is narrower: cast it in your opponent's beginning-of-combat step, before they declare attackers, and the would-be attacking force is tapped down with no attack to launch. Wait until they have already declared, and the tap does nothing, since a creature committed to combat deals its damage whether tapped or not. That is the discipline the price enforces: six mana held open telegraphs the play, and the card kills nothing, removes nothing, and leaves no lasting board edge. The hybrid pips let the manabase sit anywhere from mono-white to mono-blue while the colorless bulk stays fixed at four. It buys exactly one combat step, then asks you to already field the army that makes the step decisive.