Master Yi and Yasuo are REDICULOUSLY overpowered.
I have been in 15 games or so in past 24 hours and every single game is featuring both of these chars and often both on the same team. The only defense to either is to play them. If master Yi or Yasuo get a couple of kills they snowball immediately and become un-killable. There are detailed reasons for this.
Master Yi: His Alphastrike makes him un-targetable and does outrageous damage. If you manage to tank that and get a couple of hits on him he goes into his Meditate which means if you 1v1 him you cant kill him. In meditate he is theoretically hittable but the damage reduction is stupid high. I have seen a master yi meditate inside of Veigar's prison in a hairball of damage and then come out with ... yes, Alphastrike. He is un-hittable and unstoppable. Parry abilities like Jax counterstrike don't block alpha strike and thus he snowballs. One or two kills, he gets attack speed items, speeds up Alphastrike and literally cant be targeted. Even if you can predict his destination in Alphastrike you cant block it or stop it.
Yasuo: Again ridiculously OP to the point that if he scores one or two kills and gets an item or two he snowballs to 25/1/8. Yasuo on JUST HIS Q, has high damage, knock up, and AOE. Thats just his Q. His sweeping blade has a near instant cooldown AND a stacking effect so if he does it several times he does bonus damage. His sweeping blade reset is faster than autoattack! And since he dashes, again he becomes un-targetable by anyone not diamond ELO.
There is a reason every game with those two in it sees them with 5 or 6 to 1 KD ratios. One on one neither one is killable. If Riot examines the stats they will see that these two are ridiculously OP. I am sure the Yasuo and Master Yi players will come in and object but the stats don't lie.
What really confuses me is why Ivern is nerfed to near un-usability with his only AOE weak damage shield reduced and these two are left practically un-killable.
Finally, don't bother banning them in draft either. People just dodge the game.
Ok.