Percival
Frost 
Front row 
KnightAdamantine
Increases your damage reduction. When Percival reaches Transcendence 5, her attacks reduce the ATK of one enemy by 5% per stack for 1 second, stacking up to 2 times.
Effect: Apply Buff
Target: Self
Damage Reduction +15%, Critical Resistance +15%.
Protection
Effect 1: Apply Buff
Target: Self
Defense +88%.
Effect 2: Apply Team Buff
Target: All Allies
Defense +52%.
Barrier
Target: All Allies
Effect 1: Apply Buff
Shield: Create a shield that blocks damage equal to 80% of Caster's HP.
Effect 2: Apply Buff
Defense +52%.
Tidal Break
Inflict damage equal to 847% of Defense.
Target: All Enemies
Effect 1: Apply Debuff
Attack -24%.
Effect 2: Apply Team Buff
Target: All Aliies
Shield: Create a shield that blocks damage equal to 200% of Caster's DEF.
Character sizes
Recommended stats
About Ignore Damage Reduction %
This stat only works if the boss has passive skills giving him damage reduction. If not, it's useless.
Avalon, Reincarnation of Stars and Raids usually all have this passive, but always double check to make sure.