I have a version of this in my regular request thread, but I'm looking for one of two certain styles for this. I'm weird, I know, but here are the two general ideas.
A classic story of king pissing off the wrong person. Or creature in this case. The king had sent out troops to a nearby mountain to see if the rumors were true about a dragon being there, and if there was one, to kill it on sight. The troops did just that, finding one and annihilating it and the egg it was guarding without question.
The only issue was that this was the female, and when her mate returned from hunting for food, he found the banner to the kingdom that slew her.
Plot A (ROMANCE) Having a human form, he travels to the city where the king resides. Having a firm belief in the 'eye for an eye' system, he uses his cunning to win the princess over, and escapes with her during the celebration. From there, he plans to kill her once they're out of town, but she starts to win him over, due to his views. Unfortunately for him, he must change back into his dragon form for at least a few hours each day...
This plot would focus on the story side of it, but eventually I would prefer to have her get changed into a dragoness as well.
Plot B (SMUT) As the dragon race is starting to dwindle because of 'heroes' invading their realms, the male dragon captures the princess and takes her to his cavern. Rather than killing her off, he decides to change her into one of his own kind... (Note, this would also involve mind alteration so that she mentally becomes dragonlike as well, rather than having a human mindframe the entire time.)
This plot would definitely focus on smut, (I'd want her to be changed through sex,) and if you wanted to, there could be more victims changed into other dragons/dragonesses.If you like transformation (or mind alteration and/or breast expansion!) but don't find these appealing, here's my regular request thread.