[Chris38]

Spoiler for 50:

Like I said earlier I see two reasons why the whole rematch with Kuyou is taking place in the current arc.

First reason why such a rematch is going to occur is to show how much progress Tsukune has made compared to the start of this manga.

Second reason is to provide as with some information about Tsukune's "humanity" and the current state of his vampire transformation - it might be even possible that Kuyou is going to be the antagonist who will actually "finalize" Tsukune's vampire transformation - after all, we can't deny the fact that the whole topic of Tsukune's "transformation" has been brought up by Kuyou when he almost killed Tsukune, and Inner Moka was forced to inject him with her blood - so, if Ikeda wants to go along with the "full circle route", it might be possible that Tsukune's transformation is going to be actually finalized during his rematch with Kuyou.

Of course, it would mean that this rematch would take a lot more time then a single chapter, and personally I doubt that Ikeda is actually going to resolve Tsukune's transformation in the current arc, but on the other hand I can't deny the fact that the possibility of Ikeda leading the story in that direction exists, and that it would be quite symbolic if Tsukune's "transformation" would be resolved like that.