Avenger Armor

This armor is said to be inhabited by a vengeful spirit that pushes its wearer to fight even in the face of certain death.
While you're wearing the armor, any critical hit against you becomes a normal hit. In addition, when you are subjected to a magical effect that allows you to make a Strength or Constitution saving throw to take only half damage, you instead take no damage if you succeed on the saving throw.

Soul of the Avenger. This armor has one charge. If you're reduced to 0 hp while wearing this armor, you can use a reaction to expend a charge and drop to 1 hit point instead. The armor envelops your body and physically holds it together, as fire wreathes around you. You cannot be reduced below 1 hit point or killed until the end of your next turn, and your melee weapon attacks deal an additional 1d6 fire damage for the same duration. The armor regains any lost charges at dawn.

Sentience. This suit of armor is sentient, but rarely ever speaks. It has an intelligence score of 10, a wisdom score of 6 and a charisma score of 25. It has a proficiency bonus of +5, expertise in the intimidation skill, and is completely blind. It speaks all languages, but can communicate exclusively with its wearer, telepathically, and only does so when the Soul of the Avenger ability is activated, muttering a few sentences. With a succesful DC 15 wisdom(insight) check (no action required), the wearer can understand that the armor is verbally cursing whatever creature caused the activation of the Soul of the Avenger ability.

Cursed. This suit of armor is cursed, and attuning to it extends the curse to you. You are physically unable to unattune from it, and whenever you sleep, the vengeful spirit whispers to you. 
If you die while attuned to this armor, your body is disintegrated. If you are resurrected, you come back to life with 1 point of exhaustion. Exhaustion acquired in this way cannot be removed through a long rest, and necessitates a cast of the Greater Restoration spell at 9th level, or the Wish spell

Plate consists of shaped, interlocking metal plates to cover the entire body. A suit of plate includes gauntlets, heavy leather boots, a visored helmet, and thick layers of padding underneath the armor. Buckles and straps distribute the weight over the body.

Notes: Immunity: Critical Hits, a creature with proficiency in all martial weapons, Damage, Buff, Combat, Cursed, Sentient, Str. 15 Required, Stealth Disadvantage