In what ways is Kayn weak early?

Plus some of the highest base damage

Yeah you need to definitely need to go play him then come back.

Until he transformers, he basically has no passive and no real burst. The only way base-form Kayn becomes dangerous is if he gets fed.

He's strong early but his power does start falling off quick if he doesn't transform.

He has a healthy clear, but as for ganking it doesn't work that well. He has a show that he is coming and unless that laner is an Idiot they can easily see the dot that is a Different color then everything around them. Kayns are predictable that you just need to ward your Tri-bush and you will see them for their ganks. He eventually falls off in his base, and I mean hard falls off. His entire kit revolves around his passive which he doesn't get until he loads it up.

Nothing: kayn mains will tout this as some kind of counterplay. I had one say "you just have to invade him a lot" as his counterplay and that's how he has a weak early game....

The champ is not fun for anyone to play against, and relies on really unhealthy gimmicks to succeed. One of the worst releases in my opinion.

Weak ganking and darkin is superior in every way