Page 194 - Dragonix - DM Options, Monster Talents II

If the armor or shield is magical, the wearer must piercing and slashing damage from nonmagical
succeed on a DC 20 Wisdom saving throw. On a weapons that aren't adamantine.
failed save, Armor Class (AC) of the armor or shield
(determined randomly) takes a permanent and
cumulative -1 penalty. If its Armor Class drops to 0,
the armor or shield is destroyed.

Sword Wraiths

Stone Cursed

Commander
The stone cursed (CR 1) can have a maximum of 1
talent.
The sword wraith commander (CR 8) can have a
maximum of 3 talents.
Ever Vigilant
Type: Trait. Aura of Decay

The stone cursed has advantage to Initiative rolls Type: Trait.
and Wisdom (Perception) checks.
A creature that starts its turn within 5 feet of the
sword wraith takes 5 (1d10) necrotic damage
Hardened Skin

Type: Trait. Fade into the Ether (3/day)
Hardened Skin. The stone cursed is resistant to Type: Reaction.

Chapter 2. Mordenkainen's Tome of Foes 193