Man I didnt like the fact that you cant choose if you remain a Dragon Slayer or if you want to become a Dragon Knight, I think it would be better if we had a choice between the Dragon Slayers and the Knights.
I think that would've been interesting. I'm not sure how it could've been done with the way the story panned out... but then again, I'm not a story-writer. It does make for a compelling "what if..." though.