Riven needs to be fixed
 

Riven can Valor out of Jarvans Cataclysm when Valors only a step forward.

A lot of champs can get out of Jarvan's ult.

Mechanically working as it should. Champion-created terrain is currently coded as an untargetable minion, and Valor gives minion no-clip.

Come back when they've finished recoding major portions of the game.

Then Gragas shouldn't be able to go past Jarvan's Ult either along with a multitude of other champions.

I believe the point is that Riven isn't supposed to be able to bypass terrain. Gragas is able to body slam through small walls, if I recall correctly.

This is true, however

I'm all for nerfs to riven, but this one seems unnecessary.

Anivia wall, trundle pillar
NOPE

Those are thicker than Jarvan's ulti wall, actually. Being a radial wall, rather than a pillar or regular wall, it has a smaller hitbox.

There has been for each of them a time when Ghost would let you walk right through them; I'm sure this has been fixed already, but that's just proof of how they're coded.

There's a 20 page PDF on how many champions can get out of Jarvan's wall and how they get out of it.