Change Champions Not Items and Balance Kalista all in one

TL;DR at the bottom Before we all get our panies in a knot let me explain I choose my words carefully. Instead of nerfing the item (hello ruinglaive),nerfing the champions (hello WW), or both (hello Vladimir). Why not give certain champions exceptions to the rule. Sure it might be harder to change/code but balance would be much better. Let's start with our favorite wind walling warrior Yasuo. Yasuo because he recieves that crit bonus that GD loves has his crit damage nerfed in return. He has a unique interaction with items because he'd be broken with out this(though this is just an example try not to get to hung up on this please). So, let's talk about a recent example Taric's favorite champion Ezreal. Due to his interaction with Ruinglaive Riot decided to nerf Ruinglaive. However, why not just make it so his Q does not proc RuineGlaive?
So let's talk about the current cancer of the rift Kalista. Personally I think she is balance-able without being deleted (shocking I know) though at the moment I don't think you could without making her autos deal like 50% damage with her current interaction with . This item simply breaks Kalista. It gives her everything: AoE,Cheap Powerspike, Wave Clear, Lane Dominance. Kalista is the ADC of RuineGlaive she simply makes the item broken. Think about it. Without Runnans that stupid lifesteal build wouldn't work making Kalista easier to kill in teamfights, and it would give Kalista a defined weakness. She would become weak at switching targets which in my opinion is a good weakness for her kit. She has the ability to hard focus one due to her passive allowing her to kite around the teamfight sticking to her target and dodging people trying to stop her.

TL;DR - change specific interactions to champions who beak items such a Ezrael with RuineGlaive or Kalista with Runnans. This would finally give Kalista a weakness in her inability to switch targets effectively due to her lack of steroids being only rend.