There's not much to read about him, I'm afraid. From the codexes:
Draconis: Called "High Dragon" in common parlance, the constellation Draconis is always depicted by a dragon in flight. Recently, it has come into question whether this was the case in the ancient Imperium. Most Tevinter dragon imagery was reserved for the Old Gods, so why would they dedicate a constellation to dragons in general when specific dragons were held in such reverence? This speculation is fueled by older drawings showing Draconis as more serpentine in appearance, perhaps depicting a sea creature or an unknown eighth Old God that was stricken from historical record.
Perhaps Draconis represents the follower of Dirthamen who took the divine power?
While the subject of vallaslin is still fairly fresh in our minds... is my Female Lavellan the only one who opted not to let Solas remove hers? 
I'm not disparaging anyone that chose to agree, it just seems that people chose "yes" more often than not and now I'm wondering if I'm an odd duck?
I imagine that while my Lavellan knows the Dalish are flawed and often mistaken, she still feels very loyal to them and believes in their cause. Since the devs took forever to reveal which vallaslin represents which deity, I had to headcanon why she picked hers, and came up with layers upon layers of symbolic reasons that honored different aspects of her heritage, family, values, and life (not just the deity). So, when Solas reveals that the vallaslin were originally slave markings, her reaction was basically, "Whatever they were used for in the past, the Dalish have reclaimed them, and this is what they mean to us now." When he offered to remove hers, she just couldn't let him do it because she felt they had become part of her (whatever their original purpose) and just couldn't let him remove what had become such a huge part of her personal and cultural identity.
So, what'd you choose and why?
Terrwyn, at that point, no longer considers herself Dalish. She always wanted to learn more about her people, and the truth mattered to her more than the ignorant stability the Dalish were content with. (These are her thoughts, not mine. She is a harsh critic to others, and more-so herself.) She believes that in order for her people to move on and rebuild, they must make peace with the truth of their history instead of wild stories. So, she had them removed. Besides...she is the last remaining Lavellan; removing the vallaslin was a way to bring closure to a tragic incident.
Elgar'Asha - or Ash - will keep hers. In my headcanon, she and Terrwyn are twins. In one universe, Terrwyn is sent away. In another, Ash is sent. Ash was never big on ceremony, but the vallaslin means something different to her people now. By all means seek the truth and learn, but don't abandon new traditions to achieve it.
The two would get in a fight over their decision on the matter, but in the end look at each other, and resolve to make things better for their people.