User blog comment:IamJakuhoRaikoben/Chapter 295: Sting and Lector, Review./@comment-5263525-20120817203859/@comment-2106167-20120817204809

I'm pretty sure Sting managed to kill any dragon he might have killed just because he was asked so by the dragon itself. Either that or it fell off a cliff/died of old age while Sting was touching it.