Okay, so I'm really hoping we get to go with Solas or have him stay with us because...Solas I love you...but he's an idiot.
- He gave his ball to Corypheus (great idea btw)
- he plans on telling Lavellan about EVERYTHING then he's like "eeeeh no vallaslin instead"
- THEN he dumps her
It's obvious: Solas is shite at planning things. We can't leave him alone for five minutes. I don't think he's planning on destroying the world but by the Creators if we don't get to him soon he might by accident! HE'LL PULL THE WRONG LEVER OR SOMETHING WE HAVE TO HELP HIM. D:
We see him make a decision on the hoof in All New Faded for her when he actually see's the monster his friend has become... He very quickly verbalises all the options ("Let me think, let me think, let me think...") and concludes that a last minute attempt should be made to save her...
Unfortunately it is already too late and perhaps he should have recognised that? However, what the attempt does do is give the spirit a few moments of respite as herself and to make the conscious decision for him to kill her... Which he does... Cass is put virtually in the same situation and also eases a friend's passing...
The quest begins when we first speak to Solas in Skyhold at that point, he is attempting not to think about the trouble she is in? Why? Why doesn't he rush out immediately and save her? Perhaps he doesn't want to be distracted? Perhaps he doesn't believe she is in real peril? Perhaps he fears if he acts his true identity will be discovered? Perhaps he lacks the power to rescue her alone?
What this means is, SOLAS DOES NOT ABANDON HIS FRIENDS, even if it means a risk to himself. He is not cold or calculating, if there is a possibility of success he won't stand aside, he will act... We also see an unexpected side to him wrath... He kills the mages without hesitation.