Interesting idea. I think it should have at least a small cost though, maybe 1
or something.
Doubling the effect on the upped version would seem to be a pretty major deal though.
It will definitely have a big impact on metagame since it would allow you to cast any card regardless of quanta type.
I am more than a little worried about this making rush decks too powerful though.
Granted 30 health is a lot to pay for a first round dragon... but then again you would have a DRAGON on the first round. So much for Immolate dominating rushes.
(just a thought here: 3 card combo - this + dragon + miracle = 1st round dragon, only 1 health paid)