Everything wrong with Riven

1. She went from a one-trick pony champion to a normal, easy to pick up champion just because she is so blatantly broken and easy to play.
2. She gets 40% or 45% CDR way to easily with and runes. This makes her abilities unbearably spammable even at early levels.
3. She was unaffected by the recent nerfs to Conqueror because of how viable she is with other runes. While other bruisers/fighters got shat on by the nerfs.
4. Her CC is way too effective in trades, often canceling the opponents abilities or auto attacks.
5. She does way too much damage with her AOE abilities. This allows for her to duel or 1v2 while still being able to team fight with ease.
6. Her shield scaling with AD makes it so that she isn't punished for going full damage.
7. She's literally a stat-check because there is no real way of beating her as a melee champion if you're weaker (less items, lower level = death).
8. Immune to nerfs. Riot makes way too much money off of this champ.

Her last nerf was in patch 5.21 and that change was later reverted in 8.13 btw haHA lol xd lmao.