User blog comment:Pf987/Riven minor rework idea/@comment-4604508-20150804234121

I'd say they should increase the cooldowns on her skills substantially, but should also add in a way for her to reduce them. Reducing them with either basic attacks, spell hits, blocking damage with shield.

Another option could be punishing bad use of her passive, giving a debuff when going over her 3 stack passive limit. A slow or inability to cast until the passive stacks wear off/are spent.