New Champ already OP? How do you counter his ult? Thoughts and a serious question.
First of all, hello. Welcome to this question of mine, and sorry for the somewhat clickbaity title.
The new champion Kayn. Cool concept, but is he already too damn strong? From what I've seen, and my person opinion the answer is...sorta. So, below I list my thoughts and would love other peoples opinions and thoughts as well in a discussion about this champion.
Kayn has some interesting gameplay mechanics and it looks like some of them is just too silly. His wall walk for example. There is literally nothing to really counter this except hard cc, and there's no champion currently who can easily follow him and for most champions it means they'll have to waste a flash if they wanna try and follow him.
This champion has some silly potential to be many classes. They say his Darkin state has limited access to the backline...which is silly because he still gets shadow step as well as his Q which allows him to dash through enemies, and past tanks. It's much like Tryndamere's dash, except with a slightly shorter range. And Tryn only has that to get to the back lane, and this guy has two ways. Limited access? Not quite. Couple this with his sustain and crowd control...yay. Not to mention more %health damage from tanks. Woohoo.
His Shadow form. Gain a bit more mobility by granting his Shadow step immunity to slows! Yi eat your heart! Your ult is almost a regular ability again....with added benefits! In short, this guys Shadow form gains some benefits over his Darkin form. He gains slightly more mobility and and added magic damage. Yay. This form, imo, is less frightening than his Darkin counterpart. But with the option to flip and choose whichever one he wants to be (There was a cooldown in the video about his passive. So I'd assume he can change) is terrifying and grants such a wide array of changes and error adjustment for this champion.
They also claim his shadow form has no sustain and yet heals when he shadow steps. That seems like sustain to me.
Luckily, they didn't add true damage to this champion like a few other tanks we know....
In the end it will all come down to one thing. Scaling. How does he scale? Does he get silly 100% scaling like other tanks we know or does he get normalish scaling? Normalish scaling being typically 30-60% scaling. This will determine his overall effectiveness and heals.
Finally his ult. This is my legit question. The rest above is for discussion. Now, my serious question because this is just silly.
How do you counter his ult?
I'm being serious. I thought it was a skill shot. The reason I thought this is because the still image before I clicked play on the video showed an arrow like shill shot. Then I watched the video...it's a click ability after you damage someone, AND they become untargetable. So, how? Is he able to be blocked by Yasuo's windwall? What about Braums shield? How easy/hard is it to target them BEFORE they enter the body so you can cc them? Does cc even work?
Click abilities aren't bad, but when there is little counter to them except to "stay away" then it becomes, in my eyes, broken. Veigar's ult is one of this abilities. Yet, that one can be blocked by windwall and Braums shield. Can this?
Once he is inside there is little anyone can do. Mages or ap champs in general have options for 
but does that also freeze him? Or does his ult countdown continue and he exits before the effect is up? How does that work with it?
These are my thoughts and questions. Sorry once again for the clickbaity title.
Now, I'd appreciate it if I could hear from all of you. What are your thoughts? Your concerns? Your responses to my questions that I posed? Let's keep this civil and talk about this champion and not flame others. Thank you. I eagerly await your responses!