Zed buffs?

I main mid and while I really hate playing against Zed, he obviously needs buffs. He can't kill ADC's because of Redemption and Locket and his ult passive is almost useless because of he can only get the 5 + (5/10/15)% of someones ad when they have the most on their which is usually the ADC. I feel like Zed should get the 5 ad from anyone he kills with his ult to make him a bit stronger and scale better. Right now most mages can assassinate better then him with and I feel like he should be able to compete with them or at least not be total garbage.