Razor Barrier

Protection has always been white's answer that does its work before damage is dealt, and this is the instant-speed wrench built specifically for a world of metal. The artifacts clause is the tell: in an environment where most threats and removal were colorless permanents, a protection-from-artifacts buff turned aside artifact attackers, fogged off an artifact creature in combat, and slipped a key permanent past artifact-based targeted removal at the moment it mattered. The color mode is the more conventional insurance: blank a targeted burn spell, refuse a blocker by becoming unblockable through that color's bodies, or save a creature from a single targeted destruction spell. What it cannot do is the limit worth naming, because protection follows the DEBT rule (Damage, Enchanting and Equipping, Blocking, Targeting). It does nothing against an edict that makes you sacrifice a creature, because that effect targets the player, not the permanent; the same goes for non-damage board wipes and any non-damage removal that does not target. The targeting is what keeps the card reactive rather than aggressive: it can only protect a permanent you already control, so it is insurance, never a way to neutralize someone else's threat. That narrow scope is also why it stayed tied to the role it was printed for. A two-mana trick that does nothing on an empty board lives or dies by the density of artifact and color-based interaction around it, and the artifact mode in particular reads as a tool for one specific kind of metagame rather than a portable staple.