First, just a note, this section is for Feedback FOR the FaithWriters' site. The Open Forum is better for asking questions like these. I'm not a Mod here, so I can't move it.
I think it's an interesting idea, but I think some may get offended at picturing dragons in heaven. However, if done right, it could be a powerful story.
Drawbacks: Some have already done stories where the gods are actually demons posing as gods to trick mankind, others that the gods are the children mentioned in Genesis 6:1-4, sometimes called Nephilim.
6 1 And it came to pass, when men began to multiply on the face of the earth, and daughters were born unto them,
2 That the sons of God saw the daughters of men that they were fair; and they took them wives of all which they chose.
3 And the Lord said, My spirit shall not always strive with man, for that he also is flesh: yet his days shall be an hundred and twenty years.
4 There were giants in the earth in those days; and also after that, when the sons of God came in unto the daughters of men, and they bare children to them, the same became mighty men which were of old, men of renown.
Pro: We've seen Satan described as a dragon, and he's a fallen angel, and that he took some with him. It could be that they all have the ability to have that form. So it is a possible idea.
Con: We know that the angels cannot have salvation, or become "good", as that is a gift only given to mankind. They either stayed with God or left with Satan.
I would tread very lightly, as this has the potential to be a very controversial story. My own personal reading history, I used to read a lot of the mythologies. They have some very interesting stories, some very twisted and very non-Christian (obviously). I think blending them in a way that would not be offensive, and not go against scripture, will be a tough job.