Skarner is just too much balls to the wall, as his ult already has a really strong cc and TOO MUCH DAMAGE.
Braum should take more damage while his shield is active, he is tanking abilities for his whole team and he still takes low damage.
LB should get a bit more CD on his distortion, if you play her properly you may never catch her
Draven with the proper runes/masteries will make you explode, mainly because he is able to do a 300% crit only by clicking Q, my problem with him is one, he deals too much damage on the first Q cast.
Graves needs serious tuning, he is just doing well IN ALL THE AREAS.
Yasuo needs to get his Wind Wall nerfed so that it lasts less with a bigger CD, it is just ridiculous how it can totally make him invulnerable sometimes, even when the team is focusing him completely
Tryn needs to have his slow duration reduced
Yi-Xin, kinda true, but it is also true that they interact with on-hits too well and sometimes they are just overwhelming, mainly Yi cause of his Q, that is a blink ability, that can crit, that renders him invulnerable, that allows him to chase, that makes him super good in the jungle.
Akali if well used becomes problematic, she heals too much and deals too much damage,
Ekko needs to spend more mana on his combos.