The creature can speak. It has a name, Corypheus. We have encountered darkspawn before who use words, but none individual enough to have chosen a name. This Corypheus appears unique among darkspawn, and has gathered many of its brethren to follow it.
It would be wasteful to kill such a creature. If it can be captured, tamed somehow, its unnatural influence over the darkspawn could perhaps be turned to our favor. It is clear the darkspawn will never bow to human commands, but this Corypheus seems at times more human than beast. I have conversed with it, and though its thoughts are disordered and inhuman, it speaks of the Old Gods by their Tevinter names. I have wondered if perhaps he is no darkspawn at all, but a ghoul, so corrupted by the taint as to have become a new creature entirely.
I recommend we find a way to capture Corypheus, hold it somewhere safe from both men and darkspawn, and study its unique nature. This will require magic, however, for Corypheus's own abilities are powerful. It uses spells both human and tainted, and has a strength that would shame any magister. We must muster our best mages to face it and to hold it.