Hardened Armor is a Dragonknight Class Ability, found in the Draconic Power Skill Line.
Base Skill: Spiked Armor
|Release your inner dragon to gain Major Resolve, increasing your Physical and Spell Resistance by 5948 for 20 seconds. You gain a damage shield that absorbs up to 5121 damage for 6 seconds, scaling off your Max Health. While active, the armor returns 1 Flame Damage to any enemy that uses a direct damage attack against you in melee range, scaling off your Physical and Spell Resistance.|
Hardened Armor is a morph of the Spiked Armor base skill. The other morph is Volatile Armor.