Hello. I admire your drawing form. The main reason that I want to comment on this is that someone has claimed your work as their own: hyromatix5.deviantart.com/art/…. If this other user is actually you, sorry for wasting your time.
This needs to be in the game! Flygon should still evolve into its dragon-like form if leveled up, for fans who prefer the original appearance. But teaching Vibrava AncientPower should evolve it into this bug-form, like the cases with Mamoswine and Tangrowth. Both forms would have respective typing as well: Dragon/Ground and Dragon/Bug.