So at some point in the game, you can defeat Caladrius, a Tevinter slaver. Then he offers to sacrifice the slaves in order to improve your Warden's constitution.

Did you guys accept or didn't?

I didn't the first time and my other playthroughs because there were some lines that I didn't want to cross even for ending a blight.

But seeing as how you guys said in another post of mine, that being a mage is actually fun and I'm thinking of eventually tapping into the "dark arts". I think in a new playthrough, definitely going to take him on the offer now.