For anyone who says Kai and Jay hate each other, here is proof they don't:
In S4 when Jay said "Are you implying that I'm not special?" he looked sad in the background. But guess what else was happening in the background? Kai comforting Jay.
He also saved Jay. I know they all save each other, but Kai wouldn't hate Jay if he saved him.
In S7, when Jay and Nya were having a moment and Kai interrupted, he apologised and said that he didn't mean to interrupt, and he closed his eyes to give them privacy. (He is a Jaya shipper)
Kai also helped Jay ask Nya to be his Yang and keep the secret.
In Prime Empire, when Jay was boxed by the Red Visors in the race, Kai says "Hang on, buddy!". Then, Cole and Kai look at each other, and sacrifice their last life. Without hesitation.
In The Island, when the Keepers held their weapon to Kai, Jay put his arm around Kai's shoulders and started saying "Guys. Is all this really necessary?" And he started trying to avert the attention from Kai so he doesn't get hurt.
When Jay was 'sacrificed' in The Island, Kai was the first to free himself and then he freed the others. And when they were next to him in the ocean, he tried reaching out.
Look at that. Zane had to physically restrain Kai from going after Jay. Just like Cole did with Nya.
Then, when Lloyd and the leader were talking about 'sacrifices', Kai was mad, and he said "Sacrificing Jay cost you nothing. But it could cost Jay everything."
In Dragons Rising, when Kai, Nya and Wyldfyre were looking for Jay, Kai knew about Galamorph x-post when Nya didn't. Also, little bonus, when they were asking civilians, Kai hit the Jay pose.
Also, in a short, they were playing together. They were competing with each other, seeing who could break the most bricks for a cookie.
There is more, but this is becoming too long.
