So the idea is to move the Draconic Body effect over to Draconic Will. Buff Unbreakable Will if needed (could work like Spine of the World for instance). And make Draconic Body a new effect.
The new effect would let you shapechange into a wyrm (Draconic Body afterall

As far as what the shapechange actually does? Glad you asked!!
First of all it would replace your tile with a fricking great wyrm tile!! Do I need to go on? I thought not. But I will anyway because I love hearing myself talk.
Second of all it would remove the resist cap for the element. So a fire wyrm could have 100% fire resist. It would also double your resist to that damage type.
Third it would give you some damage when hit. Much like drakes have. The damage could scale with Con since it's a con prodigy.
Fourth it would increase your knockback immunity to 100% as well as Stun and Blind immunity to 80%. Sensing a theme here? I thought you might

Fifthly, (wow, fifthly is a word!), anyway fifthly it would give you five talent points in the breath weapon appropriate to the drake type. Pretty lame for wyrmics I know, unless of course it stacks. So lets make it stack! Why should only 'real' dragons get rank 10+ breath weapons? They shouldn't!
Anyway, that's the idea. Thanks mex for coming up with it and SageAcrin and Supermini for taking the time to hash out some ideas in IRC.
*ninja edit* This would work like temporal form basically. I figured that was implied but maybe not. So yeah, 30 turn cooldown, 10 turns of being a dragon. Or something along those lines.