Here is my breakdown of AC source
Base - 10
Dex 52 (profane 2, Mentau's 11, 7 insight) - 17
Bulwark Epic Feat (4 defensive stance) Misc. - 4
9 Martial Past lives (28 Misc. 17 Feat) - 45
Enhancements
Bulwark Aura (5 misc) - 5
Sacred Armor Mastery (Pal 3 Feat) - 3
Stalwart Defensive Mastery (Ftr 3 Feat) - 3
Aura of Good (Feat) 1
Stalwart Defensive Stance On 0
Ship Buff
Armory (Guild Bonus) Misc. - 6
Alchemical Armor Ritual - 1
Equipment
Legendary Executioners Plate (Armor with Unyielding Sentinal on) - 74
Legendary Hardened Hide (17 Natural Armor) - 17
Epic Mentau's Goggles 0
Epic Lion's Mane (5 Insight Natural Armor) - 5
Legendary Slave Master's Cloak - 14
Legendary Symbol of the Slave Lords 0
Blessed Travels (Quality Armor Mastery 2) 0
CC Gloves (7 Insight Dex) 0
CC Belt (7 Parrying) Misc. - 7
Devil's Defense (Shield 49, Misc 1) - 50
Epic Destiny
Unyielding
Unbreakable (5 Natural Armor)- 5
Shield Prowess (50% Shield Bonus Devils Defense 27) - 13
Hardened (15 feat) - 15
Twists
Grandmaster of Flowers
Walking with the Waves (6 Feat) - 6
Shadowdancer
Lithe (6 Feat) - 6
Draconic
Dragonhide (3 Natural Armor) - 3
Tensors (6 Alchemical Misc.) - 6
Total AC - 316
Combat Expertise (10%)
Improved Mage Armor (10%)
Grand Total - 379
I know I have to be missing something silly, AC eldritch ritual - 1, Cleric spell - 2 luck, augments something? Any help would be appreciated form OP or others. I need that 400 AC