Man, Tsubone really got unlucky there. Wouldn't have thought that just wishing in this particular manner to get away from the estate would already lead to Nanika asking for a fingernail. Seeing how one butler was asked for his liver, Duodenum and brain, things that would kill him when taking them away, you also could say she got lucky. Kind of badass how she didn't even flinch when ripping of that nail and even kept on smiling while threatening Killua that much with her presence alone.
Also, so many things to say about the last developments. I just adore the Zoldyck family, It's just so creepy how this whole terrible atmosphere just doesn't seem to affect them at all. They are like the Adams Family, just less goofy and way more murderous. Also, Milluki is also one sick and mean-spirited bastard, he honestly just might be as bad as Illumi, just that it doesn't seem like he's got the same power.
More revelations about Allukas ability. Appearantly, both she and Nanika can ask for requests that will lead to a wish, the only difference being that Nanika seems to come out when a heavy request has been made and the questions require you do something awful, since Alluka herself seems to be a sweet and nice girl, asking her brother to pat her, play Shiritori with her and to "die" for her (which is actually pretty creepy, but I guess that's just how the Zoldycks roll.)
btw, what's with Hisoka and Illumi now? It's been implied that they have been watching them from somewhere in the shadows, but Allukas room doesn't seem like it offers much space to hide.