Finding the archer skill Wind Flurry to be very powerful.  Two attack, no cost, no cool down?  Yes please.

The randomness of the second attack isn't perfect, but still wildly handy, and the wind  elemental effect is useful on most creatures.

May want to take a second look at the power balance. 

honestly in my opinion wind flurry is fine compared to some of the mage skills like decay which hits everything for i believe no mana cost

Mayhaps.  I've yet to unlock everything and play with all the options, am finding  other powerful abilities.  Archer gets unlocked very early, so make Wind Flurry one of the first skills to get.

Wind flurry also has a damage penalty to the second hit. I think it's a 50% damage penalty. And that's not the worst early class either for that. Dragon knight can be earned by a level 2 dragonkin as long as they take fighter as their first class and that gives an ability that hits all enemies and another that does 3 attacks instead. Or Valkyrie for Seraph or Druid for Elves Fairies and Dryads.  Alot of the race locked classes are very strong with no real penalties.