Revert Riven buff

That buff sent Riven into broken territory! Her windslash is meant to be a finisher, not an execution from 50%hp. It shouldnt be doing 800 dmg on someone who has 1,500 total hp. That means the second part of her ult does more dmg than she herself has to in order to kill you. Riven is one of those champions where, if you give her even a minor buff, it'll send her into broken territory.......let alone giving her a ridiculous super buff like riot did.