User blog comment:Asfidyll/Averyth, the Riftblade Hunter/@comment-24141319-20131118154225/@comment-11434673-20131119034322

"Averyth's basic attacks reduce the cooldown by 1 second each, but the delayed damage cannot take effect on the same target within 8 static and consecutive seconds." This means that even if you get 10203102301203 attacks off, it'll only affect them once every 8. You have both an internal and external cooldown (Zed only has an internal cooldown), which means that if you attack and apply the passive it'll go on a 4 second cooldown (external), and an if you attack them again, you won't apply your passive because of the internal cooldown on them not being up (its pretty much works like Zed's Contempt for the Weak).

Also, final executions arent meant to be weak, barely noticable damage. Its suppose to be stronger, noticable damage (ie, Darius' Noxian Guillotine or Garen's Demacian Justice).