Riven isn't actually that "terrible" to verse, in theory. [READ]
BEFORE YOU DOWNVOTE, READ THIS THREAD
Riven compared to Yasuo or Fizz is honestly a lot less worse, and here's why.
Yes Riven has the "cancer" kit, obviously, but Riven is acually in a surprisingly balanced state at the moment! (compared to season 3... oh god)
Secondly, Riven CAN'T go tanky, or she'll deal no damage. Not like other... -COUGH- -AIDS- 
Third, Riven has no "insane" aids ability, unlike Yasuo or Fizz, - [THE E], and instead is aids all around.
Riven is surprisingly, one of the better champions to verse over Fizz and Yasuo, or all those tank assassins.
is pretty damn hard to kill while still doing tons of damage.