Claustrophobia

Pacifism keeps a creature from attacking or blocking; this takes the opposite tack and shuts off the untap step entirely, which strands the creature on every axis at once: no second swing, no return to blocking duty, no activated ability that wants a tap cost. The functional ancestor is Icy Manipulator's lock, distilled into a one-shot Aura that taps on entry and then never relents. That dual reach (it walls the creature on offense and removes it from defense while the Aura holds) is what separates this style of tap-down enchantment from a pure attack-prevention effect. It pays for the broader coverage with fragility: as removal stapled to a permanent, it can be undone if the opponent bounces the enchanted creature or finds enchantment removal, though either is a clean one-for-one rather than the lopsided trade the Aura started as. And because a tapped creature cannot be tapped again, every cost that wants to draft it into service is closed off too: convoke, crew, and the usual tap abilities all stall while the creature sits there as dead weight. It is blue's quiet answer to a threat it cannot kill outright: not exile, not bounce, just a permanent that turns the problem into a fixture and leaves it standing on the board as a monument to nothing.