Did somebody say HUNTER X HUNTER ???
I am not saying I am a huge fan of the show but I may or may not have already designed ~40 Nen abilities complete with description, regulations, covenants/vows and ways of using them inside and outside of battle. That said, those who watch it, we should make a seprate thread in which we present those ideas. I'll wait till there are enough people into this.
Moving on, and addressing this to Jerry, the story so far is a huge prologue to a main story not yet written, taking place in a world outside ours. However, it is the best prologue you'll ever see with multiple arcs beginning and ending with logic and consistency. The characters are well made and multidimensional, the protagonists have goals and everyone is human, which means they feel fear, agony, pain, remorse, and there are more ethical dillemmas than in your everyday cookie-cutter-shonen anime/manga. In my opinion, the arc to begin now is the most interesting, while omitted from the anime. The villains are... as Charlotte said... just people who are in the other side. They do have their reasons and goals.
More specific stuff. Genthru is not weak. He loses due to overconfidence, a trait common to real life battlers who let their guard down when they seemingly can take their opponent blindfolded, emasculated and with one hand tied in an anchor deep in the Pacific (may be slightly exaggerating). Others are simply badass and/or genius, like Chrollo, Hisoka, Razor, Ging, the Kakin Princes. The list goes on. Even simple characters have depth and most times you'll find yourself sympathizing with those the story presents as criminals, than the ones on the "good side".
More to be said...