Looking at the Si'anwon flavour text again, the words "dream of unlife" are lower case. This could imply that it is not a dream borne from the One Dream but rather a secret that would benefit an undead being. Perhaps knowledge of possession of this could restore a resurrected creature's body to its original state, thus eliminating the problem of rotting flesh hanging from one's body that plagues thrall and myrmidons. Bah'lal could be a resurrected general who had been able to survive underwater as a glorified thrall and through his discovery of the secret, was able to restore his body and gain his status as an ancient evil. This would imply that he only used the power he unearthed in the depths of the sunken city on himself.
However, we also see "dream duel" so this argument could be ratified. I just thought this interpretation might shed a different light on the whole Bahl'al debate even though it provides no evidence to indicate the The Watcher is Bahl'al, hence the new topic.
