Blood Lord’s Armor (5e Equipment)
From D&D Wiki
Armor (any medium or heavy armor), very rare (requires attunement by a vampire)
Pale, but still eccentric. Small gleaming red gemstones cover the grayish surface, able to be concealed by the huge cloak that comes alongside it. If you can't add your Dexterity modifier to your armor class while wearing it, you can to a maximum of +2. If you can, the maximum increases by +2.
While wearing it, creatures have disadvantage on saving throws that would make them charmed or frightened on a failure. Additionally, whenever you regain hitpoints from an attack, you extra temporary hitpoints equal to the hitpoints you gained.