@Zblader: not sure if want. I'd prefer the dragons staying vanilla, though those are interesting ideas.
Well, Aether Dragon is Immaterial already. A +1|-1 per turn would actually be a pretty good idea, but my concern is that by the time you get these Dragons out you could've already won. What if Gravity had some way of transforming random quanta into Gravity quanta for a quanta acceleration method? It fits the theme, and is contrary to Supernova (though I imagine it would be used with it). Would also be yet another pseudo-counter to Discord.
Aether Dragon is Immaterial because Zanz did not want to balance mono Parallel Universe dragons. Massive Dragon should remain vanilla unless it cannot be balanced as such. That said, I think evidence is accumulating towards that conclusion.
That leads to the question : can Massive Dragon be balanced as a vanilla card?
I feel that would either result in a stat change that shifts it more towards the other dragons which still leaves it conflicted with the midhitting Charger in terms of speed, similar to
Stone Dragon vs. Steel Golem
or
Crimson Dragon vs. Seraph vs Phoenix
. IMHO, preserving the series theme it is important but we also have to consider serious underuse and card role conflict that Massive Dragon suffers from in general.