ULTIMATE COOLDOWN REDUCTION : [5% (+3% per stack), up to 20% at max stacks] ⇒ 5 (+4% per stack), up to 25% at max stacks
One of the goals of runes is to give champions options about what tree they go into based on how they want to play. Domination is a tree about burst, which should make it appealing to some of the burstier marksmen, but there is no real keystone for them. Hail of Blades should help spell-based marksmen who want to lay down a swift chunk have a keystone to promote that playstyle.
HAIL OF BLADES : Gain 50-100% (at levels 1-18) attack speed for the first three attacks made against enemy champions.
NOW NOT LATER : If more than 1.5 seconds elapses between attacks this effect will end
CANT STOP WONT STOP : Hail of Blades allows you to temporarily exceed the attack speed limit
COOLDOWN : 5 seconds out of combat