well....i don´t think that sort of concept is healthy. It´s always gonna end up as a "win-more" condition (either you stack and stack and stack or you get shut immediatly and that´s it). Just like when devourer scaled to infinity. That sort of concpets would be alright if the game only would consist of professional 5v5, but as most of it is rather chaotic SoloQesc environments - you just can´t have "weakish if focused/forced early on" as a tradeoff for insane power if not stopped. Because most of the times the coordination needed to abuse the weakness is just not there, while the execution needed to abuse the power of that trade is just really easy to pull of.
Edit: my idea for rageblade - give it an active that trades the stacks for 0,5sec of AS-cap per stack and a jump with 100range per stack to the target...just letting out all the rage. And maybe add an upgrade for lategame, the main reason on-hit/hybrid builds aren´t all that popular is that the slot efficiency on most champs is really bad and it´s just a snowball-thing.