The ride home so far was uneventful, leaving Kai plenty of time to ponder over his situation. Shuzen mostly left Kai alone, despite his promise to talk to him. At first, Kai wondered what Shuzen could want to talk about, but after he was unable to think of a concrete reason despite thinking through millions of possibilities, he left the question of what to be answered some other time.
The better question would be why. Why did Shuzen's entire demeanor change after fighting the Chucadori? As far as Kai was aware, that beast wasn't one known to be parasitic. Some beasts invaded bodies and in rare cases even took over their motor functions, but this wasn't one of them.
As far as Kai was aware, anyways. Out of all the aspects of beasts he found interesting, this topic definitely wasn't one of them–it was far too terrifying a prospect. As a kid in his former life, he would always imagine walking down an entirely innocent street just for some beast to take over his body.