his Top winrate is 41% and his Jg winrate is 43%. Darkin form is better than shadow assassin by far, but its still a tad bit underpowered.
Buff his ult scalings in shadow assassin, Buff his base dmg on his abilities in Darkin form, and give him a compensation nerf to his scalings.
KaRniVooL1335 voteseverything is OP when you are bad at the game
Tails901612 votesTeam has no CC 
:"Wow Kayn is so OP gg"
KaRniVooL133 voteswell if i was EZ i would go blue build and get a GA so i have armor vs an ad melee/assassin
and use my Arcane Shift on super low cd with cdr while having an aoe slow on sheen procs and kite
King of Mongoose18 votesif you were ezreal the best thing to do would be to ff at 15 and submit a ticket to riot support reporting yourself for picking ezreal
picking ezreal is the equivalent of inting
RainXBlade5 votesPicking ezreal is the equivalent of inting
Looks at Mastery Level 6 on Ezreal
I'm sorry bud.
Throws it in the trash.
Picks up Nightbringer Yasuo with Mastery Level 7.
But seriously, Ezreal right now is too niche to be a viable pick against anything. The only way you can probably get ahead as Ezreal is that the enemy team deliberately walks into your Q's.
Dj0samaSpinLaden2 votes[{quoted}](name=King of Mongoose,realm=NA,application-id=3ErqAdtq,discussion-id=8JnHUkfQ,comment-id=0005000000000000,timestamp=2017-07-20T00:37:04.226+0000)
if you were ezreal the best thing to do would be to ff at 15 and submit a ticket to riot support reporting yourself for picking ezreal
picking ezreal is the equivalent of inting
Thank you for being a speaker of truth. Everytime my team hovers ez I beg them not to or dodge. Super minioms do more damage to champions than ezreals not in diamond+
King of Mongoose6 voteseven in diamond+ ezreal does no damage
Muted Summoner2 votesTeam has no CC
Grab Fiddlesticks and the dude is trash more so than Yi cause at least Yi feared with his ult will run away from the team he was running into.
Subject 513 votesI'm thouroughly convinced that he is absolute dog shit until he hits late game. At that point, he can get pretty insane - but even then, his kit makes him just . . . it's just bad. Like, really bad. At least his late game is good - but that's because Lethality and AD items are busted at the end of the game. It isn't him.
The problem is that his kit is so overloaded that if he was in a good spot, it'd be a problem most likely. He can, after all, ignore walls and even leave SR.
Rux1002 votesAgreed, there is so much going on with his kit that he is one of those champs where he's either ridiculously terrible, or severely overpowered. Unless they change something, he will never be just right imo.
I'm not at all as good as other people at this game, but if you ask me, I say tie is passive completely to his ult. Upon level 6,, 11, and 16, take how much damage he has taken against how much damage he has dealt, and let that decide wether or not he goes blue or red. I know this isn't perfect but it's just an idea to start the tweak on him.
TL; DR: Give him less control over his form so that it will be safe to give him a buff somewhere else.
AirKingNeo6 votesUpon level 6,, 11, and 16, take how much damage he has taken against how much damage he has dealt, and let that decide wether or not he goes blue or red
That sounds horrible. People are picking Kayn for the flex of both forms. Some top Kayn players only want red mode.
Profirix3 votesMost players only want Raast (red). It is the only viable form currently.
My Waifu Vanilla3 votesYou aren't wrong. SA is ENTIRELY feast or famine and snowball reliant while Rhaast is only "sort of" feast or famine, but can still fall back on his tank busting and actual cc. A Shadow Assassin that isn't ahead is worse than a cannon minion since he isn't killing ANYONE (while being the only thing the champion brings to the table), while Rhaast can at least somewhat shred tanks and drain tank as a bruiser with decent hard CC.
Wimbledofy9 voteshow is his kit overloaded?
khorney1 votesap does more damage the whole game rather then just late game like ad is. for ad ez to be better his e or w needs to have some ad scaling increase
Wimbledofy3 votesy did you reply to me
NinjaGuy699 votesI believe Meddler said they're planning to buff the AD ratio on his ultimate for his Shadow Assassin form in the next PBE cycle.
Other than that, I do think that base Kayn is somewhat weak but it's probably intended because he's supposed to unlock his actual power spike when he transforms. I'm one game away from getting Mastery Level 5 on him and I can definitely say that Shadow Assassin Kayn is super underwhelming (hence the likely buffs to him next patch). I think Rhaast is mostly fine though.
AirKingNeo3 votesOther than that, I do think that base Kayn is somewhat weak but it's probably intended because he's supposed to unlock his actual power spike when he transforms.
The problem with that is it makes him terrible, or at least lack luster. as a jungle until the mid game.
NinjaGuy694 votesThe problem with that is it makes him terrible, or at least lack luster. as a jungle until the mid game.
That's just how the champion is supposed to work. His clear is pretty damn fast and he has a lot of good gank paths with his E but he needs to work for his upgraded forms. I like it because it makes the champion more skill-oriented instead of just giving him power for free in the early game and making him obnoxious and unfair like a Lee Sin or an Elise.
Profirix9 votesForce a champion to duel others to get more powerful, but don't provide enough tools/power to get there...
r4ndomkill3 votesfor those who dont get it 
BoilTheOil8 votesmax w first and woah hes suddenly better
Grjjm Reaper1 votesMax Q first, for easier heal burst
W 2nd
R third
E last
dont forget 
and 
Core item no matter what
r4ndomkill1 voteshis q gains 20 damage a rank. and his w gets 45 damage a rank.
ChaosThief1 votes20 per hit, a rank. So 40.
It's also much more spammable. It's for jungle clear rather than ganks.
AirKingNeo2 votesFor jungle you max Q.
For top lane you max W because once you get Darkin mode, your Q no longer scales with rank. It's always 50% AD + 5% HP damage each hit.
r4ndomkill1 votesthats what i was thinking. toplane his w is better as a poke tool and does comparable damage to a full q.
YumaS2Astral1 votesWhat do you think would be the best mastery for lane Kayn? Fervor of Battle, Deathfire Touch, or Grasp of the Undying?
GayFluffyUnicorn2 votesFervor i'd say. Atleast every high elo kayn i've seen top took it. And that's the only mastery i used anyways. You are not going THAT tanky and while the sustain is nice corrupting does its job. Many toplaners will have armor and rush tabi so the 7% armor pen is pretty nice if you want to trade/all in you need to AA a lot since his CDs are very high.
Tl,dr: fervor is the only viable choice in lane imo.
Grjjm Reaper1 votesFor jungle you max Q.
For top lane you max W because once you get Darkin mode, your Q no longer scales with rank. It's always 50% AD + 5% HP damage each hit.
I think your confusing shadow form with darkin, shadow form has no scaling with Q, buy darkin keeps scaling
AirKingNeo5 votesI think you're being stupid because Darkin Form Q is always 50% total AD + 5% (+4% per 100 AD) Max HP damage AT EVERY SKILL RANK where as Assassin Form keeps the same damage ratio as base Form.
Dj0samaSpinLaden2 votesmax w first and woah hes suddenly better
This^^^ I have spammed this champ, one token from mastery 7. I always max W its damage increase is soooooo good early and mid game. I also almost exclusively play shadow assassin unless we need cc or to shred tanks. I Think he is a balanced champion and he feels made just for me good job rito.
SwiftKitten887 votesyour right he isnt op... lets keep him that way... and as people actually LEARN how to play him his winrate will increase and we can get an accurate reading...
lets not be completely stupid and buff him like stupid people and have him be like a 60% winrate 
One Ashe On6 votesPersonally he is balanced. If someone get the hand on him, he is fairly good and fair to play against. I actually like to see a Kayn in my game because i find him appealing and nice to look in game gameplay wise and visually wise. Kayn could use a bit QoL on assassin form and i would be top shine. I don't own him but plan to because he look fairly well designed . Something that haven't happened for a while with Riot.
Grjjm Reaper4 votesmake his passive scale off AD but do magic damage and we are in business
One Ashe On2 votes[{quoted}](name=Grjjm Reaper,realm=NA,application-id=3ErqAdtq,discussion-id=8JnHUkfQ,comment-id=00080000,timestamp=2017-07-19T23:01:32.360+0000)
make his passive scale off AD but do magic damage and we are in business
That would be a good and interesting idea !
Edit: I wish i had Kayn so i could get your icon but Rip :(
r4ndomkill1 votesdoesn't kayns shadow forms bonus damage already count as magic damage. i only ask because someone at riot was replying that they did that to make sure his damage would have to go through two forms of mitigation to prevent it from being insane.
Grjjm Reaper5 votesit's per level magic dmg, not scaling ratio
TwitchInMyPants2 votesHell yeah, I love weird AD scaling magic damage like (old) Yorick E. Its a unique way of promoting early-midgame play while having a bit of fall off later. Its obnoxious for tanks but since you're primarily AD it ends up being fair enough since armor will reduce most of your damage, but not all.
Jorencice4 voteshis Top winrate is 41% and his Jg winrate is 43%. Darkin form is better than shadow assassin by far, but its still a tad bit underpowered.
Buff his ult scalings in shadow assassin, Buff his base dmg on his abilities in Darkin form, and give him a compensation nerf to his scalings.
Buffing base damages is almost never good.
Then he can just build 6 tank items and be unkillable.
tieger057 voteswell no, not to that extreme... maybe just a slight base dmg buff to Q
Grjjm Reaper2 votesrhaast already does that
AirKingNeo2 votesStop spreading the false narrative that Death's Dance is "overpowered" on Kayn.
Grjjm Reaper3 votesyour putting overpowered in the sentence when there is none
Deaths Dance is merely an essential item...
AirKingNeo2 votesNo it isn't essential.
My Waifu Vanilla2 votesI mean it is pretty close. It gives Rhaast literally every stat he could ever want while also synergizing INCREDIBLY well with his kit. It allows Rhaast to play much riskier and destroy tanks much easier than BC would since he actually gets AD from it and gets a MUCH larger heal on his Q+R against high health targets.
Cowseed2 votesI first timed him in ranked today and won. Never mind the enemy team had an afk and it felt less serious than normals, we won!
But on a more serious not if you check statistics people are using fervor on him for god knows what reason and I believe that has something to do with his winrate.
NinjaGuy693 votesBut on a more serious not if you check statistics people are using fervor on him for god knows what reason and I believe that has something to do with his winrate.
Underrated comment. Not sure why people think Fervor would be good on a bursty assassin.
Kloqdq2 votesHis feast or famine. I fucking called it upon his reveal. Either he'll get feed and carry, or he'll get set behind and be useless. The champion is cursed.
Giggling Granny2 votes"Ivern is not op wtf riot this champion suck"
3000 buffs later and when people learn him he become stupidly strong with 61% win ratio"
Same with yasuo Same with skarner and so on
So no you people need to stop asking for buffs when you dont know how to play a champion