Frost Breath

Tapping a creature buys you one combat step; the no-untap rider buys you the turn after that. Where most blue tempo tricks pin a single body, this one spreads the same effect across two, and the doubled target count is the design lever: one card neutralizes a pair of would-be attackers or strands two blockers offline while you race. The reach has a cost, because tapping leaves the board exactly as full as it found it, so the tempo it banks has to convert into damage before the targets wake up. The instant-speed window is the whole pivot. To stop an attack outright, cast it before attackers are declared (the beginning-of-combat step is the clean spot), tapping the threats out of combat entirely; tapping a creature already declared as an attacker neither removes it nor stops its damage. Vigilance is no defense, because the keyword only stops a creature from tapping itself to attack while Frost Breath taps it regardless, so it can bench a vigilant attacker that never had to tap on its own. The rider works on already-tapped creatures too, applying only the no-untap clause to lock them down for the coming turn. Sequencing matters because the spell taps what it targets: aim it during an opponent's end step and the creatures stay tapped and locked through their next untap step rather than stranded untapped. A clean, narrow tempo tool of a kind blue has printed in many shapes, sized here for breadth across two bodies rather than depth on one.