Increase damage reduction effect & special defense
Piercing
Ignore damage reduction effect & special defense
Fury
Increase damage boost effect & special attack
Calm
Ignore damage boost effect & special attack
Note
Damage reduction & damage boost effects include arena damage, faction damage, attack boost and reduction, DoT damage boost and reduction, and all-damage boost and reduction.
Fury and Piercing do not entirely ignore what Shield and Calm have — they counter each other.
Example
20% Fury ignores 20% of Shield stats, and vice versa.
Specialised Attack and Defence are added directly.