Guardian Mastery

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.