Aaryonar guards the entrance to the main ring of the northern wing.
He will come to the aid of any other dragons if agroed before he is killed except the 5 in the very northern hall.
Casts Call of the Zero roughly every 10 seconds.
Casts Cloud of Disempowerment roughly every 20 seconds.
While it seems he will always come with his guards if they are agroed, he can be single pulled from them. Beware of the guards and Aaryonar's long agro range, and that the top step leading to him is extremely slippery.
Pic by: Harlee Quinn, Nox Mustale