Hanna's Custody

A pure prison-hatch enchantment: it makes every artifact on the battlefield untargetable, yours and theirs alike, and the symmetry is the entire point. The card walls off an entire permanent type from interaction, and shroud is the bluntest possible tool for the job. What gets rewritten is the artifact removal war: anything that needs to point at a specific artifact (the Disenchant family, the Shatter family, targeted Stone Rain variants for artifact lands, even an opponent's own pump or sacrifice ability that wants to target a permanent) simply has no legal target while this is in play. The friction is that it cannot read the table. An artifact-heavy white deck protects its own engine, but a deck running this without a stake in artifacts is paying three mana to disarm a removal slot it could have left in the opponent's deck. Shroud, unlike its later cousin hexproof, blocks the controller too, so even your own beneficial targeting (equipping, repairing, untapping a key artifact) gets locked out. The asymmetry players want from a protection piece is exactly what the keyword denies, and the card lives or dies on whether you actually want artifacts to be touched at all. It is a wall, not a shield with a door.