Honestly this interaction reveals so much about Isagi’s dynamic with others, ideally he wants his rivals to challenge him and force him to grow. In turn, Isagi challenges them and forces them to grow.
Isagis rivalries will always hit for me cause he almost never really destroys them. Barou, Rin, Nagi, Kaiser, every loss to Isagi just makes them come back stronger. He is more of a catalyst. I genuinely love that