The Dragon Feasting Ritual, as introduced by Charles Brown when he was acquiring his Pet Beasts, is a unique method that allows the Netherflame Wolfhound to consume Dragon Blood Insects in order to acquire a dragon attribute.
The origin of the Dragon Feast is impossible to trace, but there are rumors that it was created by an ancient entity attempting to usurp the Dragon's Bloodline. No one knows whether it was successful or not, but this ritual was passed down and collected by the Alliance and other powerful forces.
The reason why Dragon Blood Insects are used is that they are born from the soil of Yellow Spring and they are incredibly pure with their simple dragon attribute, they don't have much intellect, only the instinct to evolve and to reproduce quickly. They are like a swarm of containers carrying pure dragon blood, making it easy to plunder.
Oh... much like chives planted in the ground, one crop after another.