Now that we know for sure how Hidan fights, it made me think back to how he and Kakuzu fought Yugito. So far as we know, if a jinchuuriki dies, the bijuu dies, too (maybe). Which is why Gaara wasn't killed (until the extraction) and why Kisame wanted to cut off Naruto's arms and legs, but not straight out kill him. And, of course, why Naruto was able to demand "rent" from Kyuubi. It looks like Hidan stabbed his heart -- just as he attempted to do to Asuma. This would kill Yugito, of course. I thought maybe he stabbed himself in the chest afterwards, as part of the whole ceremony -- but he's in the circle, still transformed, so it would kill her, too. Assuming he did in fact stab himself in the heart (which he may well not have), can any one think of a decent explanantion? edit: it's kinda low on her body for the heart... but still, getting stabbed in the vicinity of the liver or spleen just isn't healthy, especially since Hidan had been laying there for 30 minutes.