Armor of Spite

Armor (any heavy), rare (requires attunement)

Unholy glyphs engraved on this black iron magic armor burn with a faint, orange light. While wearing the armor, you gain a +1 bonus to your AC. At the start of your turn, you can choose to allow attack rolls against you to have advantage. If you do, the glyphs shed dim light in a 5-foot radius, and you can use a reaction when a creature hits you with an attack to force the attacker to take necrotic damage equal to twice your proficiency bonus.