Runes are associated with Dreams very closely. We know that in order to learn the Dream you must find the Rune that it relates to. In the case of the Dream of Unlife, it is buried under The Deep at Si'anwon. that is the only Dream so far that the exact location is known.
Now I doubt that a Dream can be destroyed or else the Trow would have simply destroyed the Dream of Unlife and secured that all 49 Dreams would never be united. If a Rune Stone could be destroyed then the Dream itself would still survive, but in another form.
Now we also knowerful mages can be reincarnated multiple times. But for some reason each time they are reincarnated they lose a part of their previous life. Balor became more powerful after each of his deaths. Shiver on the other hand lost power. So is there a handicap along with being reincarnated?
We also know that no mage has found all 49 of the Dreams. Mazzarin was considered among the more powerful Avatara of the ages, but was slain by the Watcher just before Connacht rose to power. It seems to be a quest of sorts, where each Archmage must traverse to all 49 Dreams before being proclaimed the victor. Let me know what you think about these ideas.
Sincerely,
Pimpy™