As a Riven main, I have to agree her cooldown on her E should be increased. Its effectively like being shielded around half the time. Not by too much tho. 10 or 12 seconds at ability level 5 is plenty. That makes it so she, with 45% CDR, either has to wait 5 seconds or 6 seconds for her E again. I would humbly like to ask that her shield time got bumped up by that half a second, tho. That kind of wait for a 1.5 second shield is kinda painful.
EDIT: Personally, I wish they went the distance and delved more fully into her fighting game inspiration and made her E a sort of Shoryuken, where she has 0.5 seconds of invincibility and knocks the opponent back JUST a touch, like maybe just outside of melee range or something.
Basically I'd prefer if her kit was more centered around dodging than blocking.
EDIT #2: Whoa... I support a Riven nerf as a Riven main and I DOWNVOTED? I think I love you all...
[zombie-nunu-hearts]