The user compresses a large amount of chakra built up inside their body and changes it into a dragon head-shaped fireball. The user then skillfully manipulates that great fire, and attacks their opponent. Even outside of the attack range, its power and reliability are stressed. The flames have a high temperature, which can create an upward movement of air currents which in turn can give rise to thunder clouds. A master of this technique can fire off several flames in succession and anyone caught in the technique could potentially be reduced to ashes.
This is part of the setup that Sasuke uses in order to perform his Kirin technique.