How to balance resourceless champs like Riven,Yasuo

Using Riven as an example: Raising her cooldowns will make her weaker. Dropping her damage will make her useless. Her utility is already on a low duration. so how can she be nerfed while remaining viable? Its not that she has all of this in her kit,or that its free,its that its always up. My idea is: Create a debuff like the ninja thing where using a single spell repeatedly within a short timespan gradually increases its cooldown. That way, these champions actually have to think about how they want to use their spells and not hit 230 cs at 20 mins for free. you can finally feel safe when you see your minion wave and will actually have a worse laning phase (sort of) as for champs with energy,you are on your own. champs with a health cost don't seem bad until its a single target spell. Thoughts?