Kayn is without a doubt the ultimate Weaboo wet dream.
Denounced Noxus for Ionia, Has a demon that battles for his soul, thinks he's superior to all other Noxians. Worships the shit out of Ionia, Makes edgy remarks to everyone, has a Ninja Master/Dad, Has a ninja waifu (akali), and the worst offense is his freak Hair.
look at it, look at the bangs, look at the length, remember he fights up close. So how hasnt it got him killed yet??
The short answer: Because he's a joke.
The long answer: Kayn is not intended to be taken seriously. (At least, I sure hope not.) He checks off so many Anime Edgelord boxes it has to be intentional. And I'd argue it works. Unlike a lot of edgy types, no one respects Kayn or takes him seriously except his ninja dad and sometimes Rhaast. Akali thinks he's crazy, Aatrox ignores him in favor of talking to his scythe, and so on. By going that deep into the Arrogant Edgy Anime Guy cliche, Riot shows how hollow and pathetic such a character would really be.
Without his 'demon,' Kayn's a completely empty character. Compare baseline Kayn's dialogue with Rhaast and Shadow Assassin's. Baseline has a bunch of fun interactions between Kayn and Rhaast. Rhaast is genuinely funny, in an over-the-top violent sort of way. Shadow Assassin Kayn, though...he just goes even further into the Arrogant Edgy Anime Guy cliche. He's defeated an ancient evil, mastered his dark powers of darkness, and just generally has an ego and hairdo to rival Aurelion Sol. But there's no real depth aside from him sounding a tiny bit sad if he kills Zed in-game.
Kayn is ultimately not a Cool Guy. He's hollow.
EDIT: Oh, and the hair thing probably isn't a problem. You've got like a third of the roster with long hair that could easily get in their faces and they generally do okay.
His waifu is Jinx.
and the worst offense is his freak Hair.
You mean Riot designed him to basically be Sasuke.
Only champ with long hair who wouldn't logically be in danger, and only because he has enough Nox hair cement in it to use it as a weapon.
To be fair, Rhaast doesn't give a shit about Kayn's soul. He just wants his body.
Kayn, the Edgy Twinkboi
Worships the shit out of Ionia
Not really?
If you really want to nitpick, there are several champion designs that are nonsensical.
