Grave Ward Armor

Armor (light, medium, or heavy), very rare (requires attunement)

This armor bears gold or brass symbols of sunlight and sun deities and never tarnishes or rusts. The armor is immune to necrotic damage and rusting attacks such as those of a rust monster. While wearing this armor, your maximum hit points can’t be reduced. As an action, you can speak a command word to gain the effect of a protection from evil and good spell for 1 minute (no concentration required). While the spell is active, if you are reduced to 0 hit points, you drop to 1 hit point instead. Once you use this property, it can’t be used again until the next dawn.