Their vitality it truly unmatched, yes. The only thing that can kill a dragon on Myddvai is the combined force of all the others. That is how they keep one another in line.

[Tearing one apart is nothing so long as it was not the force of all the dragons doing so... Armis will be fine to stay in pieces. Ives would argue he should stay that way the longest of the lot.]

I have my theories, but I do not wish to share them. I think it is best you Pulled provide an outsider's insight to the mystery. We here all have our biases... it clouds our judgement.