The Inner Flame of the Dragon is a type of magic featured in The Inner Flame. It is a rare form of power that fewer dragons can possess. It gives the dragon the power for all their abilities to be at their purest. They even obtain abilities regular dragon can't do. A sign that a dragon has this flame are flames in the scleras of their eyes.
The Flame can make a dragon so anger, it can change into a fearsome form, unlike the accelerated aging from greed.
The Inner Flame is merely an ailment the young has to go through in life.