I was reading through the Legends and Lore stuff about who the head is, and I happened to notice that the Head being a former Leveller, Moagim, which is what my theory has been for a while. Think about it, a they say the leveller never dies, they always remove his head and dispose of the body in various ways. Balor was trying to talk his way out of getting tossed away AFTER it had gotten removed, so he wasn't dead. Also, he probably wouldn't die after getting thrown in the Great Devoid, it's just there's no way for him to come back because no one is going to jump in after him to try and rescue him. So the head is Moagim, formerly Tirecies(sp?). If Balor, a leveller, can survive a while with his head cut off, you would assume that any leveller can for any length of time. So they buried Moagim's head and later on Alric realized that they could use the Head's hatred of his former enemy to get revenge because Alric knew it was Connacht who was Balor the whole time, or at least suspected. He is the head Avatara so they all listen to him in his idea to dig up the head to help them, maybe not knowing of Alric's theory of Balor being Connacht. Now, Connacht was the hero of the particular age in which Moagim was defeated. The Wolf Age, i believe was the dark age. Then the light age was Wind Age perhaps. Anyway, don't you think that Moagim might have a little something against Connacht, even if he is Balor. Not only did he defeat him and bury his head in the sand, he took over as the leveller, stealing Moagim's thunder. So now Moagim has a thousand years to mull over his defeat and let his rage grow. Despite the fact that all of them are evil, Moagim might want to get a little revenge on the people that ended his reign. So he had both Shiver and the Watcher killed because they were part of the Light back then. He probably knew of Connacht's quest to find the armor and other artifacts, and its doubtful he knows exactly how much time passed while he was buried, so he doesn't know that Connacht/Balor has already obtained it, or is decieved by the Dark in order for them to capture alric, or even, due to him being evil, just decides to trick them. So the head is Moagim. He had the power to survive buried under Muirthemne, and also had the thirst for revenge to help the Light.