Veilstone Amulet

The trigger reads like protection, but the mechanism is an instant-speed shield that arms itself through normal play: cast any spell and, for the rest of that turn, your opponents cannot point removal, burn, or targeted abilities at the creatures you control. The key window is the stack. Because the protection keys off a cast trigger rather than a resolution, you hold up an instant and fire it in response to an opponent's removal spell; the Amulet's trigger resolves first, your creatures become illegal targets, and the opponent's spell fizzles for want of a legal one. That makes it reactive in the best sense, defending an alpha strike or combo turn at the exact moment an opponent reaches for the answer, with no need to commit the protection ahead of time. The cost is precision. It does nothing against board wipes, edicts, or any effect that does not target, and it covers only the turn the trigger fires, so it guards a single decisive turn rather than standing watch between turns. As colorless artifact protection that asks for neither a body to defend nor a spell of any particular type to trigger, it tries to make a fragile board immune to interaction for exactly long enough to win, and it sells that immunity at the price of covering only what an opponent chooses to target.