Issa is, at the moment, pretty much an enigma, but I think that we shouldn't except him to make any appearances in the current arc.
The reason, being the fact that he is probably weaker compared to his wife (Gyokuro), lover (Akasha) and his pretty powerful daughters - well, maybe apart from Kokoa, who seems to be the only one, who's power development is the most "normal" - in other words, that she reflects how strong a vampire of her age is.
Of course, I don't think that Issa is weak, compared to an ordinary vampire, he is definitely superior, it's just that the females surrounding him, are definitely far from ordinary, which leads me to think that he was only capable of keeping his position, because of Akasha, who was, more or less, capable of keeping Gyokuro in check.
When that influence has disappeared... well, we see the results of that, in the current arc
Of course, when I'm talking about Moka, Kahula, Akua and Kokoa, I mean there potential, once they reach a similar age as Issa - at the moment, I have no doubt that he will still prove to be a strong enemy against them, since he is older and has more combat experience / time for his powers to develop compared to his daugthers, who are still, more or less teenagers / young women, who definitely haven't reached their full potential powers yet.
Back to the next chapter discussion, I can't wait to see how Inner Moka is going to react once she notices that Tsukune's aura has changed - after all, I doubt that something like that can remain unnoticed, especially to Inner Moka, who knew the feeling of Tsukune's aura, before he underwent the human modification technique.
While, I doubt that she will question him about this, in the middle of a battle, she will definitely going to have a lot of questions to Tsukune, after the current fight is over.