I've actually been toying with a Dragonic Scion (so, yeah, not a lesser dragon either) idea for a bit now and I took it in a completely different direction than you Sancta. I've put natural True Shapeshifting as the focus with a high mental fortitude (Discipline and Conviction) to balance. Fits in with the whole "We are what we wish to be" (one of the aspects I've got tied) nature of Dragons. This also anchors you to being human still at your core.
With the other 5 refresh, you could put into modular abilities (so you can grow claws, become larger, etc.) and keep investing into that power to reflect you getting more "dragony"; at 5 you can shift to a form with Inhuman Strength and claws to do some major damage, Inhuman Toughness and Flight when you need to survive, etc. Think of it as tapping into your dragonic nature but you can't access all of it at once yet. More than that, the inherent weakness is that you need to spend a full round shifting those powers out, which could be thought of as you needing to concentrate to tap into your dragon side.
Either that, or Sancta's suggestion of Sponsored Magic, which would fit nicely with a high Discipline and Conviction to boot.
I want my fellow to be Marked by Power to a Dragon, so I'm thinking of getting the extra point to do so by tying the modular abilities to non-human forms (so, Human Form +1 covering Modular Abilities). It's a nice touch and mean that if you want to tap into your draconic powers, you've gotta look the part and break your disguise cover.
Just my 2c. I'd love to hear thoughts on what I've got as well!
