The issue with Kai'sa isn't her on hit damage

Lowering the damage output from her passive and shit is cute but that's not what makes her broken.

The issue is the damage she can't miss from her missiles and her enormous shield that she gets for playing aggressive.

There is no reason for her shield to soak up like 500-600 fucking damage with the mobility it has.

And there's no reason for her missiles to do a shit ton of damage to multiple targets when you can't dodge them.

Lower the damage on the missiles and lower the shield she gets from R, and she's fine.