I feel that these least few chapters are well done if you take them for what they are, but when I look at the series as a whole, I honestly feel like this probably happened too soon. I feel like we JUST found out that these dudes even knew each other (if this was mentioned earlier then I totally forgot about it) and that this fight was so deeply personal for them.
Structurally it's really good so I'm able to forget that the timing was a little weird. If Goryuu was meant to be a character building device for Tsurugi which tells us that he ain't number 1 for nothing, then it certainly accomplishes this and I love that this series cherishes it's power scaling, allowing even the MC to hit her ceiling in the face of a major villain. This creates a powerful baseline that is the world this story takes place in, the characters that live within it and rules in which things operate and it emphasizes that these things matter.
Also makes it more impactful/disappointing when inevitably the MC plot armors through all that shit, but I hope that doesn't happen.