Me and Fallen were talking about ways to kill him, while technically splitting him up won't kill him we talked about it.

Going along the idea of magic being used to keep him going, it is why he is basically a shadow of himself. Like he was semi-resurrected he is all there but at the same time his flesh and bone is missing (Fallen said I could put this down to Duuri but I cannot recall if she said she had an idea or if I was to come up with one). Probably cruelty in the fact he is just bones.

Hence, the reason he still feels pain as if flesh was there which can relate to the fact how he can still walk and talk as if his flesh were there. About killing him, if you want we can add destruction off his skull to the list however there is also the fact that you can completely obliterate anything he is (all the bones), find a way to remove the magic from him or force him to overexert himself in his use of magic. That is going along the assumption that part of his magical ability comes from him manipulating whatever is holding him together and if he cannot control it effectively he essentially gets rid of everything holding him together and starts to turn to dust. The more he does this the longer it takes him to recover and even once he grows back he'd still have to wait to make sur ehe was at his strongest and just wouldn't fall a part again. E.g. Tank and a Water Trough. You want to keep the Tank Full or he starts falling to pieces but if it fills up and continues to fill it goes into a trough and that he can use. Of course unlike a normal trough it will have its limits to how full it can go and how much power each moves depends on his practice. 

(An easy way to destroy him would be find another mage who can do decay magic to decay him bone by bone.)

[quote=Lucius]plus Virgins are hard to come by. [/quote]

Self sacrifice?