Yasuo change
So i think the main game play issue with yauso is that he has almost no cdr on his kit. The lack of cdr means that he almost never worries about when to engage he just does.
The biggest offender in this case is his "E". A skilled Yasuo will know how to use it to always get away. The only cdr it has that it cant be used on the same thing for X seconds. This free movement skill he has makes it very hard to finsh off a wounded yasou. The constant jumping through things if done right can make it impossible to catch him.
I personally would like to see an ammo system instead of the unlimited uses that "E" has. Give 3 max charges with a 10 sec cdr per charge. This would allow Yasuo to still do hit and run tactics but kill a lot of his free movement speed.