I love that we're being shown how Isagi trains. The attention the author pays towards the process of growth is one of the best parts of Blue Lock. Getting to see each player's thought process and the specific skills they use to execute their plans is so dang satisfying. Its like Hiori says. The moment everything clicks into place it looks like the player suddenly evolved. But because we get to see and understand each step of their process, it makes the payoff even more exciting.
In this chapter Isagi shows a a lot of good expressions, but my favs have to be pages 15 to 17. I love Isagi's motif of dissolving into puzzle pieces whenever he's thinking. The reason why Isagi is so quick to adapt and take in new inspiration is because he's willing to destroy his existing preconceptions. When he disagreed with Yuki's or Barou's thinking, he didn't leave it at "I'm right and they're wrong". He actually reflected on it and learnt something. In Yuki's case he realised there is no one rational way to play, every player plays according to their own ego and priorities. For Barou, he realised that you can't force someone to cooperate with you, which means you need to be the one to adapt to them. And at the end of the match Isagi gives then credit where its due and apologises to
them. Its something anyone can do, but to Isagi its second nature. That open-mindedness is what enables him to learn so quickly.
I'm so freaking excited to see how Isagi performs after all his training. Since Igaguri mentioned mastering his technique for "anyone who dares challenge me on my right side", my guess is Isagi wants to improve his direct shot. Which is why he went to Kunigami, who excels at physical ability. Maybe he's gonna find a way to stop getting knocked off balance like how Kaiser or Sae did to counter him.