Tis whole post s crap, soulblighter is assumed to be able to make soulless according to flavor text in myth 2.
your speculations are pretty bad, i mean IMO i think the creation of undead is a pretty simple matter, your speculating that bacause thrall are named after bahl'al their finder, that he's the only one who can make them when it makes more sense that lots of people can create thrall. Its like saying newton discovered gravity, therefore he's the only one effected by it.
And dreams are NOT all objects, or shiver, and the deciever would have ammo for there binding dream and whatever shiver has. I would say most dreams are not ammo dependent.