Guardian Mastery Feature 19
You are known for your suit of armor more than the person inside. Your proficiency rank for your guardian class DC increases to master. While wearing armor, when you attempt a Reflex save to avoid a damaging effect, such as a Fireball, you can add your armor's item bonus to AC instead of your Dexterity modifier; if your armor has the bulwark trait, increase this bonus by 1. If you get a success when you do this, you get a critical success instead.
Traits
Anything that doesn't list another rarity trait (uncommon, rare, or unique) automatically has the common trait. This rarity indicates that an ability, item, or spell is available to all players who meet the prerequisites for it. A creature of this rarity is generally known and can be summoned with the appropriate summon spell.