This abiltiy has been the long coveted resurrection that dragons were wanting, just liike super res only on an hour timer and a hoard cost of 5k. To separate this from the distinction of another super res spell, make it so that it can resurrect the caster itself. For example if a dragon were solo hunting and just pulled one too many mobs and dies, they can res themselves on the spot by using primal rebirth, even if they were dead. I just think of this as an extra way to make it special and unique to us.