Well if the theory that Solas is Shartan the elf that helped to lead Andraste bring Thedas into monotheism. Solas's game could be to adsorb the essence of the deities of Thedas to become the long awaited Maker, and sealing the weakened deities in mirrors. If this was the plan, it would explain why Flemeth wanted the old god's soul, and then turned in both her essence and the old god's. She was playing collector/co-conspirator taking the old god's power, while having Morrigan seal the soul in her son.The question is with the Anchor gone how will his plan play out? The Breach could have been Solas's way of bring the deities of Thedas out of hiding, but he lost his trump card. He can take their power by force, but what if one of these deities is to strong to seal without the Anchor. If another deity's soul was to mix with Solas and corrupt him it could be worse than any blight.
That is a very interesting thought. Especially when you think about how Solas acts when you enter the Fade physically with him. Of everything that's in front of him, the thing that he's all like "LOOK! There it is!" Is the Black City. Solas has been walking the Fade in dreams for a pretty long time....I mean, this is not the first time he has seen it. I think he actually says "close enough to touch" or something like that.
I don't know if Solas wants to become the Maker, but I do think it's a very real possibility he wants to get into the Black City.
On another note of being in the fade physically, I had a thought. When you run around there are broken eluvians all over the place. And, since there was a giant crazy Nightmare demon nearby...doesn't this mean that nearby there was some individual that had some sort of fear or anxiety over broken eluvians? I know that could have just very well been some reflection there regarding Solas, but couldn't it also have been some reflection of nearby pantheon members......in the Black City.? I mean, they would probably love nothing more than to see a working eluvian....