I'd like to share my last games experience against a Yasuo
Let's start off by saying that I won the game.
I played
into 
A few weeks ago, I was rank 250th Cassi in the world at D5 89 LP, before I tilted my way down and had a series of unfortunate events to put me where I am now, I say this so you know that I know Cassi mechanics.
We came out of laning phase with
at 0/3/0 and I was 7/1/4
I had 2v1 Yasuo and the enemy jungle, and destroyed the Yasuo 1v1.
Then the
rotated bot lane to split push while I team fought on other parts of the map. My bot lane
rotated bot to stop the split push.
It so happens that when
rotated, he bought before hand and hit an item spike
.
Can you guess what happened? Enemy double kill, Yasuo 2v1 my bot lane. after being starved of kills and experience early game, and some CS, he still managed to destroy my bot lane.
This gave Yasuo some gold, and let him snowball a little bit.
The game proceeded on more lengthy than it should have BECAUSE Yasuo could now kill and team fight efficiently, even though being so far behind early game.
The issue with
is actually his entire kit, he needs a complete over hall, not a small one. The items he buys makes him good because of the quickness that he can deal his damage and weave around his windwall. I really think Riot screwed up on the basis of even creating a champion of this kind.
could be half an item ahead of the enemy
and still easily lose a 1v1 to him. She's a team fighter, not a duelist. Whereas Draven excels at shredding single targets. Draven winning this fight doesn't mean that he's broken. It just means he's better at 1v1ing other ADCs than Miss Fortune is.