@pyromonki:
It should also be noted that there are apparently multiple ways to "fulfill a request".
Alluka asked for Killua to die, so he "Played dead".
It's probably safe to assume, that if the butler earlier had a liver for lunch like someone here suggested, that the request would've been fulfilled upon giving it to her.
In other words, fulfilling Alluka's requests can be a mental battle in itself, as the request is fulfilled by Alluka's own definition.
The only problem with this, is that Alluka wasn't pestering Killua at all, they were just playing brother-sister games, the pestering will start when she'll start calling Killua by his name in stead of "onichan".
–- Update From New Post Merge ---
@RobbyBevard:
It'd be nice to believe that he just tangled himself up in a knot with the scale of the ant arc and legitimately needed the breaks to work through the story points and get around it being a big fight saga, and that it'll be smooth sailing from here on.
I don't believe it, but it'd be nice.
Yeah, writer's block, could be possible, I want to believe it.