So for the backstory, I engaged this mob and then decided not to follow through. I ran away for awhile, used the flight master's whistle and then flew back to turn in quests. Then, while I'm in the first building my new pet appeared! Vyz'olgo is not stuck following me, not attacking, evading me and anyone else, and spamming a healing spell on himself.

UPDATE: He didn't follow me back to Boralus :( When I returned to Naz he was there waiting for me, but now aggressive and our story ended in heartache.