Well, I don't know if you beat that dragon already, but I would advice you to never go beyond level 15 without a good reason. At levels 16 and 17 you cannot access Merlin's shop, which really helps with its specialty uses.
If you haven't beaten it yet, then my other advice is to stick to it. Not all the dragons are nasty as heck.
And one last thing: if you are having problems with the dragon after becoming a Knight and before becoming a Lord, I'm 99% sure you still have some exploring to do!
