Once the game expands a bit more (which it most likely will), then we'll see more strategies, more strength in mono- and duo-color decks due to a larger variety of cards per element....
This is simply not true. When more cards are added, rainbow decks with scale more than the mono or duo element decks. Consider any scenario you like, all creatures, mass shields, it doesn't matter.
Rainbow gets 3X the quantum per turn that mono and duo do. Evening out the elements in your rainbow deck, effectively makes it as powerfull as a mono that got 3 quantum per tower. with 4 lands rainbow gets 48 quantum in 4 turns, mono gets 16 quantum in 4 turns. Adding variety to mono does not change this fundamental problem and also adds more precise variety to rainbow. Literally compounding the problem.
Thinking it over again, I think the easiest way to balance everything would be to nerf false gods a ton, and nerf quantum towers. The only other alternative is to increase the cost of every card in the game so that mono actually lets you play things faster than rainbow which is not the case now.
(really only quoted so I could reread as I typed)
The problem with Quantum Towers is that the Quanta they give is always randomized. I can't tell you how many games I've lost because the one Quanta I needed was the ONLY one that the Towers never gave me. I've lost games midway (about 20 cards left in my 55 card deck) because I was sitting at 4 Aether the entire game. It's not fun. The point is, even WITH Novas, it is ultimately the luck of the draw and getting lucky enough to get the Quanta you need from the Towers that wins the game.
Just because Rainbow gets three quanta per Pillar per turn DOES NOT mean that it's the same as a normal Pillar that gives only one quanta per Pillar per turn. Normal Pillars ALWAYS give ONE Quanta to the element that you need. Quanta Pillars MIGHT give zero to three quanta to an element you need. There are twelve elements, which means that there is a 3/12, or 1/4 chance that you will get an element that you need. Also, with such random quanta production, you may not get the amount you need until it's too late. Sure, this can be off-set by Novas and Supernovas (which you'll still need your Entropy Quanta for, unless you're running a Mark of Entropy), but then you'll rely on getting a (Super)Nova early game. Otherwise, they'll just be a useless draw late game, which would simply be a waste of a draw for the turn, when instead you could've drawn something that could actually be useful.
Also, even if adding more cards to each element would give Rainbow more to work with, what I was getting at is that there will be far less counters to other types of decks in a Rainbow deck. The standard ones I see playing now are usually 47-60 cards (aside from Scaredgirl's Scarab Rainbow Deck), which means that there isn't much room for improvement. Sure, cards could be taken out, but once you start adding some more, you'll need to off-set them with more Towers, which would make the number of cards you could add even less. Also, with the new cards, Rainbow decks just can't add them willy-nilly without screwing up their Quanta per card balance that is so vital to the deck running smoothly. If, for example, Dual Pillars were released (similar to Dual Lands from MTG), then Duo- and Tri-Element decks will become MUCH more popular. Even if those were the only new cards added, both duo- and tri-element decks would not have to worry so much about relying on a specific type of Pillar, since all the pillars in the deck could produce at least one element that they would need, greatly speeding up the effectiveness of the deck. Rainbow decks, on the other hand, would only suffer from these types of Pillars being implimented.
