WHM Trait (Stonewall): 5% chance on regen (non medica II) tick that your next Stoneskin cost 0 mp and can instantly cast.
DRG Ability (Penta Thrust): Absorb the effects of Choas Thrust and Disembowl on target to multiply Potency of next 5 attacks by 3. (Recast 300s)
WAR Ability (Insurgence) : Lower Maximum HP by 25%, while raising damage dealt by 25% and lowering enmity. Under the effect of Insurgence, certain abilities will grant Rage. Each unit of Rage increases potency on all abilities by .5%. When five units are stacked, you will become Inflamed. (Ability can be used to increase potency by 5% for 8 seconds).

Just a few I thought of at work, have many more but no time!