Flurry is a skill located in the Dual Wield (which can be found in the Weapon skill tree). Flurry is a base skill, and can be morphed into Rapid Strikes
Flurry deals the following types of damage: Physical Damage. Which means that it gets buffed by the following blue champion point trees: Mighty, Piercing, Precise Strikes, Thaumaturge. Also the following red champion point trees protect against this skill: Hardy, Thick Skinned.