Well, Tyson and Kai are the main characters in Beyblade and are also among the strongest players in the game. Now, some people do wonder as to who among Kai and Tyson is a better blader.
BEYBLADE SEASON 1
In the first season, when Tyson faces Kai for the very first time his blade gets destroyed by Kai. At that time he didn’t have Dragoon. Tyson challenges him shortly afterwards when he gains Dragoon and the match is a tie. During the tournament Tyson defeats Kai in the first round. Kai manages to beat Tyson in the second round and Tyson is able to beat Kai in the 3rd round by a slight margin. However, Kai does beat Tyson after gaining Black Dranzer when they face each other for the final time in that season.
BEYBLADE V FORCE SEASON 2
In the 2nd season, Tyson manages to beat Zeo who beats Kai.
BEYBLADE G-REVOLUTION SEASON 3
In the 3rd season, Kai and Tyson battle again for the World Championship and Tyson ends up winning by a few seconds. Both Kai and Tyson were exhausted from previous matches that day and Kai wanted to be on even terms with Tyson while facing him. Kai goes the extra mile to face Brian and Spencer, before facing Tyson so that Tyson is not at a disadvantage. So, considering both players were equally exhausted before facing each other, I would say Tyson won the battle fair and square. Some people might argue that Kai had a more intense battle before compared to Tyson but I don’t think that we can absolutely say that as a conclusion.
Beyblade Rising Manga (Season 4)
Now, first of all Tyson has won most of the major battles against Kai and has managed to beat players who even defeated Kai. In their last battle(World Tournament during G-Revolution) which was shown clearly, Tyson won the match against Kai.
However, later on when the manga for Beyblade Rising was released, it was shown that Kai won the last battle with Tyson which happened in the last episode of Beyblade G- Revolution. The result of that battle was not shown and the season ended just when they started the battle. So, Kai finally won the last battle between him and Tyson according to the manga of Beyblade Rising.
However, I am not sure if we can conclude Kai is better than Tyson. However, it is interesting to note the following points.
Beyblade can be viewed as a team sport if you consider the person and the bit-beast to be a team. Well, yeah in that case there is definitely a strong argument for Kai to be a better blader as most people would say that Dragoon is better than Dranzer.
Another theory which supports this fact is that while Kai had Black Dranzer, he was absolutely unbeatable. The rest of the Blade Breakers (Max, Ray and Tyson) had to unite to beat Kai as Kai had beaten Tyson by a clear margin during their battle. They had to unite and also use original Dranzer to beat Kai with Black Dranzer.
Now, there was another strong opponent called Brooklyn in G-Revolution. Brooklyn beats Kai the first time they meet. Kai undergoes depression and is shocked at his loss. But he comes back to beat him when they meet in the tournament.
Kai was able to master the hard metal system in just a few hours to and is able to defeat Brooklyn. Brooklyn after that battle faces Tyson and the winner is not really shown clearly. We don’t get to see whose blade stops first. Tyson in that battle clearly uses a lot of help from his friends as their bit-beasts can be seen uniting with Tyson’s blade to support him in the match. We can probably assume that Tyson won that battle, since BEGA is destroyed and BBA is restored. But again, it is an assumption not a conclusion. The fact that Kai was able to beat Brooklyn on his own speaks a lot about his ability.
So, well you can decide as to who is a better blader between Kai and Tyson. At the moment, Kai has a strong case to be better than Tyson.