Heya! So, in a way that's situational — basically, dial down powers enough that you don't struggle to justify why your character isn't just breezing through every mission, or destroying the world (hey, some folks have that ability!) in response to being summoned here. Because that would get boring for your gameplay experience pretty quickly.

If you want my take: dragon shifting should be okay. Maybe now and then, if the party is in a smaller venue (think: a ship!), we might have to come up with a McGuffin that explains why Wrathion briefly can't revert to his dragon-y self. Otherwise, I don't really see his dragon skin as a problem, personally.

That said, if you feel Wrathion might become boring or unplayable for you, because he'd have too easy of a recourse in every situation, you could maybe make it so that it's harder for him to sustain his dragon form as extensively. Alternatively, you could assume it uses up more of his power than usual to shift and remain dragon-like. But ultimately, I'd say to go with whatever will give you less long-term trouble when you face a mission and think, 'Damn, I'd love to challenge my dude, but he'd just dragon his way out of (X) and I can't ICly make it work.'

Does that make sense?