I speculate it comes from the overwhelming amount of time he spends in the Fade. Specifically, he naps in ancient ruins where the Veil is extra thin. I assume doing that causes one to have a more intense Fade experience than most. Perhaps after a time of so much exposure, he learns things within the Fade realm. Beyond that, maybe Solas is slowly but surely becoming permanently "altered" by spending so much time in the Fade. It must have some kind of permanent, lasting effect (or damage?) to the brain. And since demons and spirits exist in the Fade, capable of attaching themselves to mediums (which it sounds like Solas is "medium material") then perhaps one of those creatures are altering his perceptions, carrying over to the real world. Remember that the Fade is just a distorted version of Thedas, like an alternate dimension. (Sorta.) If Solas is capable of lucid dreaming, then that means he can easily navigate his dreams (and the Fade) and retain information collected from within. It kind of feels like him being an elf is somewhat irrelevant compared to his habits that which are likely altering his conscious state of mind. It's probably like dropping acid one too many times, to a point in which differentiating reality from distorted reality becomes a struggle. I assume Solas will start off confident and able to hone his treasure seeking abilities, but that will evolve into an obstacle for him as he loses whatever sense of control he had at the start of the game.
Interesting theory! I like it.
I wonder if this ability will somehow go hand in hand with Cole being able to hear that song/sound (my memory of Asunder isn't the freshest, must read again) in those ruins. The Veil there was pretty thin as well, no?
On a side note, I just played my elf mage in DAO the other day and just came across the point where you are told that if the fade you were in wouldn't be pre-set by the one who made the scenario (more or less), then you'd be able to conjure up whatever your imagination allows.
=> Would Solas be able to make himself super-powerful in the fade if just his will is strong enough? Will he be able to 'disolve' enemies, because he is not used to find them in 'his' fade.
Since he wasn't raised with 'the monsters from the fade will overtake you if you waver' has he even ever encountered a being like that or would he be able to encounter one? I imagine if one of his companions joins him in the fade and 'expects' that kind of enemy to pop up, he'd run into one cause that companion 'summons' one without wanting to...
@Oswin:
Blackbeard SHOULD have his Warden senses tingling when there is Darkspawn nearby.
Cole... I'm not sure about. He can hear something that I currently forgot... *see part of post above*
Dorian... definitly should scratch that itch. :3