whirling blades+faster atack and vaal clarity???

I guys i have see a nice build and this play im now :)
but in hes build he say a 3 link whit whirling blades+faster atack and vaal clarity and he can use it as a aura and can easy spam whirling blades but i not? i can onley use the clarity when it full and canot use whirling blades? why? sry for my bad eng -.-

here the link to the build thanks
https://www.youtube.com/watch?v=MEMlcLfTuP0

i have the the prob. this aura is not the glarity waht he use its Discipline ^^ but i have no idea why i can use whirling blade and im not

2 possibilities:
1) You don't have enough mana
2)Only works with daggers, claws and one handed swords.