Flurry

Stance. For 5 seconds, your attack rate is increased by 33%, but you deal 25% less damage.

Stance. (5 seconds). You attack 33% faster. You do 25% less damage.

Acquisition[edit]

Very useful for Assassins in PvP, as most of their damage comes from attack skill bonus damage, which isn't reduced by Flurry.
Most common stance for IW mesmers, since Illusionary Weaponry ignores Flurry's damage reduction.
Heroes don't seem to use this skill.

Anomaly.Similar to Life Attunement, the descriptions fail to state that the 25% damage reduction only applies to base damage.