Not the anti-hero you think he is.

Kai is an absolute Gigachad and there is plenty of evidence to back it up.
Starting right from the beginning he punishes his lieutenant in the Blade Sharks after humiliating Tyson right at the start of Beyblade.
Straight up flexes on his opponent to prove a point to Emily about data.
When he loses to Johnny he straight up beats him later without any need for a growth arc.
Takes a humiliation from Spencer like a pro, doing a much better job than Kai's own teammates of curing him of his emo phase.
In V-Force he comes out of retirement because he enjoyed battling Dunga.
He's the one who hires Hilary as coach for the team seeing sense in her back to basics training regime.
Kai saving his teammates multiple times in V-Force.
Any fight Kai wins in G-Revolution is absolute gold, this includes the satisfying beatdown of Brooklyn.
Probably his most noble action and one that really elevates Kai to legendary status, silencing the crowd who were booing his opponents the Allstarz and demanding they show respect to all competitors, something I wish more sportsman did.
This is why Kai is S tier, his only black mark being the Black Dranzer saga but I blame the writer who clearly came up with that after watching Majin Vegeta episodes of Dragonballz.