@Had1u4 most likely that Orsted displayed his dominance through his (intense) stare. And due to his curse, pretty much every living being that encounters him will only have "fight or flee" instinct going off at an alarming rate, the dragon probably realised it picked a fight with the wrong person since they aren't stupid creatures. Orsted has been described to have piercing eyes so it probably is one of the factors as to how he chased off the dragon easily