Rageblade has never been a healthy item.
I feel like ranting for a bit.
Rageblade has never been a balanced item. The idea of an attack speed hybrid item is cool but very few champions really make use out of it. The only champions that actually use it are ones that can abuse its terribly overload passive when on the right, and very few, champions.
The main champions that come to mind when I think of Rageblade are Master Yi, Vayne, Kai'sa and old Kayle. Vayne abuses her W passive, Yi abuses his E and passive, Kai'sa abuses her passive and old Kayle kind of used the item like it was meant to be used. Now Neeko abuses her W passive with it and is most likely going to be nerfed because of it.
I dont even think Rageblade should work like it does now. Vayne, Neeko and Yi only use this item because it stacks their three (four for Yi) hit passive faster. Honestly, it shouldnt work like that in the first place and it's crazy how strong Yi and Vayne are once theh build it because of this. They arent over powered by any means unless they have this one terrible item.
It shouldn't be allowed to stack anything other than onhit damage. Then we can actually give the item itself more stats and the champions that abuse it real power added on to their kit. Maybe changing Rageblade to do 50% of onhit damage dealt as bonus true damage with every second auto could be a cool buff to it. Making it even harder to itemize against the champions that want hybrid damage. That's just off the top of my head though.
All the champions that are viable with rageblade.