Note for GMs: The following item has been made intentionally stronger, this is because in its original printing the author put a high value on the challenges that were required to attain it. Caution is advised when granting it to player characters.
Penitent’s Prayer
Armor (leather), very rare (requires attunement)
These robes bear the symbols of ancient yokai, said to the be the first of their kind. Some yokai feel that their war with the humanoids was a betrayal of these ancients, and that peace was always a possibility. Such yokai wear these robes as atonement. A powerful protective enchantment is woven into their threads, but it only manifests in times of utmost peril.
While wearing this armor, you gain a +1 bonus to AC. When you are reduced to 0 hit points, even if you would be killed outright, you drop to 1 hit point instead. Once used, this property can’t be used again until the next dawn.
Ref: T&H p166