Yeah, we know about your deck; I was suggesting something different. This has the advantage that it can be used without rares and works unupgraded as well.
Relax. I'm not saying this deck sucks and mine is better. I'm just saying maybe Fire isn't the best choice if Earth has cards that will do the same thing. Usually if you design a duo deck instead on mono, there is at least one card from other element that you have to have. I don't see any "have to have" cards in Fire (IF you have Pulverizer). The Earth/Gravity I posted also doesn't need upgraded cards but it does need Pulverizer. So if you don't have Pulverizer then yeah, Fire is the best way to go (because of Explosion).
That being said, I think most rainbow decks out there would destroy this deck. In my opinion the biggest issues are:
1. no permanent protection (your shield WILL be stolen)
2. only 7 Earth Pillars in a deck of 30 cards.
3. only 2 characters with 2 HP each (Rain of Fire anyone?)
4. Fire Lances but only 6 Fire Towers (+mark)
5. difficult if not impossible to penetrate Bone Wall
You might wanna consider dropping a couple, if not all, Earthquakes. Reason why Earthquake is so effective with Seism, is that he's a False Gods who can push out tons of characters early. So you have no quantum coming in AND you get pounded by tons of characters. Human players cannot do both, so even if you manage to destroy Towers, your opponent just uses Supernova to get that quantum he needs. Very rarely have I seen a situation where you can totally shut down a rainbow decks quantum production. If not for Novas, Earthquake would be awesome.
And Protect Artifact is a must imo. That one card is usually the sole reason why I go Earth. I cannot imagine why you wouldn't take it if you have permanents like that Shield?
Like you yourself said, this is "Hypothetical" deck. So you haven't actually tested it?