It shouldnt be like this. I mean after introducing so many important characters, you should go through it to the end. Whatever happen to Sari and Tatsumi? How will their life fold? How about Kyouya and Alex? Unless there is sequel manga for them. Is there???
From my point of view (and Im sure from many other point of views too), Narsus's drawing is definitely the biggest mystery that must be unveil. (⌒▽⌒)