I am left wondering where to go with it now? While Zertorme wanted the baby dragon, I don't want him to turn and immediately crush them in a fit of pique. I was thinking he might take the long road of getting them into his service, serving him loyally and that way he has the dragon and it's 'master' working for him. I was thinking this might overcome his anger at losing his wyvern. Does that seem reasonable? I don't want him to be a raving villain as I think he sees himself as too much of 'the hero' for that.
And the dragon. What the heck to I do with that?!? Obviously it will be awhile before it grows to a size where it is more than an exotic looking cat. But equally, I don't want the party to never see it mature. I was thinking that maybe in six months, with enough food, it would be at least pony sized. Heck, if a PC with staningist can change the Ravenlands, why not a draconic king? I did tell the player that of course, it would take 8 seasons for the dragon to grow up, but we would rush the ending on the 8th because I'll want to change systems.