Heh, look at all the dragon killing going on in this thread all of a sudden. 
My little elf mage wrapped things up in the Emerald Graves today, including hunting down and slaying The Greater Mistral. We had scouted it out briefly before while going to spread some ashes over the side of a cliff. As an aside, funny moment here: The ashes blew into Sera's face, and she coughed and complained. I think it kinda grossed her out.
Anyway, I quickly realized my little elf mage would not be able to face the dragon, equipped as she was to be a cold-damage-dealing death machine. So, we diverted back to skyhold to change things up. I crafted her a new fire-damage-dealing, dragon-slaying-rune-infused, guard-building masterwork staff -- which...just... holy crap, it almost feels like cheating!
-- and some new warden battlemage armor, decked out with great bear hides for the cold resistance.
I could have solo'd that dragon.
With a few energy barrages to build up guard (thanks to the fade-touched obsidian in the staff) and barriers (thanks to the knight-enchanter's Fade Shield), my little elf mage didn't take a single point of damage.
Oh, it was beautiful.
Sigh. Anyway, now that I'm done with the Emerald Graves, I dunno where to head next. Should I go back to Emprise de Lion, and at least wrap up Blackwall's personal fetch-quest? Should I go to the Hissing Waste? Should I finally go and deal with the Grey Warden problem? Hmmm....
EDIT: I know, I'll go back to the Storm Coast and see what Vinsomer is up to. Lightning dragons are vulnerable to fire right? 
EDIT#2: Vinsomer's head now holds pride of place in the Skyhold Trophy room, even if I still dunno where that is. My little elf mage practically did have to solo this one. Cassandra, Blackwall and Sera didn't last very long against all the lightning, and the vortexes, and the slashing, and the clawing, and the biting, and... well, you get the idea. Sera outlasted the other two, which was kinda surprising given how quickly the Greater Mistral wiped her out. But, when I say she outlasted the other two, it was maybe by a minute. I tried to keep them all safe with barriers, but I couldn't replenish them for the others quickly enough.
Vinsomer is a tough one; he puts up guard quite often, and it takes a lot to punch through it... although it might just have seemed that way because my little elf mage was the only one left doing any damage. But the dragon's guard didn't last long against her spirit blade; slice, dice, chop, lunge, jab and it was gone, and I could get back to whittling away the beast's health. Took some damage this time, but only at one point, when VBlackwall and Cassandra went down. I dunno what attack Vinsomer used, but it destroyed everyone's guard immediately.
Anyway, the score is: Little elf mage 6, dragons 2 (the Fereldan Frostback killed us twice).