It always seemed more probable to me that the Head was an Avatara from the Wolf Age, one who served under Connacht during his defeating the Trow and such, and later was one of the first to attack Connacht when he became Balor...possibly on Connacht's orders (if, as suggested in Wolfa Age, Connacht had any idea he would become Balor and was destroying items of power or burying them away. The Fallen Lords game does say he did this, so it is logical to assume either he knew he shouldn't be able to get his hands on them in case he turned, or that someone close to him might turn and use them.)
If this is correct, then he could well hav been an ally of the Deciver's before the Deciever was turned. It would also seem to me that the Head was pretty much doing everything to benefit the Deciever...which gives me an idea.
We know the Deciever and the other Fallen Lords couldn't get along, suggesting that if the head was another Fallen he probably wouldn't want to work with the Deciever.
However...what if the head was brought back to life, using a combination of Balor's and the Deciver's magic, and by doing this the Deciever created a plant? Basically a magical item that would serve Balor by feeding the Light false information, then they left it burried and until they felt it would be of use.
Of course, if the Deciever helped in its creation, he would leave himself some control over it. Hence why it gives the Light information on how to defeat Shiver, and why it essentially handed Alric right into the Deciever's hands.
But if Balor became annoyed by the fact the Deciever was using a tool that was meant to benefit himself, or that he wa aiding in the destruction of the other Fallen Lords, he may of sent the Watcher, who has hated the Deciever for a long time, to destroy him. Once the Deciever (and the Watcher) were gone, Balor took control of the Head himself and bided his time a little before starting up the civil war. Maybe he was hoping to draw Alric's attention back home, giving him time to prepare, or maybe he figured once he'd dealth with Alric and the rest of the world was in flames he could march through what was left of the Western armies and win Madrigal easily.
Or maybe someone should stop letting me have sugar. Your choice
