Dragons strike me as not caring for the spoken races. Since the 7 great dragons all survived through Umbral Eras (before getting killed by mortals) I'd imagine they "prepared themselves" either hibernation, dragon magic, etc. Most likely dragon magic due to Nidhogg, with one (borrowed) eye, created some type of magical barrier in the Aery, which would protect him and his brood if it weren't for Cid. So I'd imagine most surviving Great Dragons at the time cast a barrier to protect?
Eitherway, I'm sure they were giddy at the idea they were killing each other in droves and may have known that Asciens were involved, anyway
