I think NeoCybercoin may have a point though. Akua and Fairy Tale are at the Fong's for some reason, getting some of Moka's blood may just be it. Their plans are suddenly coming to fruition, and Kahlua recently admitted that she wasn't the only sister that had been brought into Fairy Tale. With the rest of the monster world in chaos because of all the other operations they have going on, now may be the opportune time to go for Moka. She's away from one of the Dark Lords, and though she may have gone to another one of them, she's certainly no longer in the barrier that surrounds the school.
It makes sense in this chapter after learning about Alucard, but before we knew about that, there was never any reason to suspect that someone like Akasha, much less any vampire, was the third Dark Lord, much less the leader of them. This chapter was full of foreshadowing that it was Akasha, but there wasn't any prior to this one.