The twelve True Gods knew something else.
That was a secret known only to those who had befriended the three dragon kings in an era when the Charioteer still lived and the Dragon Kingdom had not yet been established.
Since "Frost" is the controller of ice, she holds concepts like "Stillness", "Hatred", "Lament", "Annihilation"; while "Char" is the master of flames, representing "Passion", "Joy", "Intensity", "Rebirth". They form a set of perfect Dual Aspects.
Whenever the power of "Frost" strengthens, her vitality weakens, and "Char" weakens accordingly, while his will and vitality grow stronger; the reverse is also true. Like cold and heat—similar yet opposite, unable to coexist—they are like the two poles in an hourglass.
Just as winter and summer alternate, spring departs and autumn arrives.
Then what about their brother, the Black Dragon known as "Ash"?