Fire Chase

Nightwing and Twilight (both are dragons) are hunted down by a team of two terrifying dragons. when they get them to speak and tell them who made them hunt them down they said, "HE told us to hunt you down- said you were a threat."
Wondering who HE was they go on a journey filled with life-threatening danger (and some serious butt kicking is involved) to find out who he is and what he wants.